Hi,
Does anyone know the denomination of the thread between CMCx preamp and MKx capsule?
Measured Nominal Diameter is 19.30 mm, pitch approx 0.5 mm, single thread, right hand.

Billy Idol - Sweet sixteen
YouTube

Carpenters - Ticket to ride.
YouTube

Taking dawn - The chain
YouTube

Hello everybody,

I've a company creation project, to produce an high end plasma speaker, not talking of those" arcs" or "sparks" toys on youtube...
but something with good distortion and sound levels specs.
I own plasma speakers, and I have work for years on cold and hot plasmas.

I'm interested in what you would really like...
Any requirements, features, design ideas are welcome (Wich sound input you would like etc...)

Technicals specifications :
(a full range is a dream but not achievable due to excessive power consumption)
Low cutoff frequency :

Price :
Wich price would you accept to buy a pair ?

Thanks for your comments.

Pa

Hi,

I wonder if it would be possible to add an AES output port on a china dac that is based on amanero, I have replaced the china amanero with a original one latest version, and I wonder if it might be possible internally add a aes adapter by piggyback the i2s signals from the amanero card mounted inside the dac.. just feed the aes adapter with 5v/3.3v and the 4 i2s data lines. That the amanero will share the signals to both the dac board it's mounted to and then take same signals and send to the separate amanero aes adapter board. Anyone know if this would work? Or anyone have a solution to my idea?

When comparing native DSD and I2S formats, they seem to be quite compatible. IMO two I2S/PCM data lines could be used for creating a native DSD interface. The 32 bits of each DSD channel could be split to two 16bit PCM channels, using 4 PCM channels (= 2 I2S interface data lines) for each DSD channel pair. RPi5 could output 4ch DSD256 (8ch I2S at 176.4kHz running with 32bit frames bclk = 32fs). RK 3308 (e.g. Rock Pi S stamp module) could output 8ch DSD512 (RK3308 I2S runs ok at 16ch 384kHz). Only the bit clock and data lines would be used, the frame clock (LRCLK) would be ignored.

IMO it would "only" take an alsa-lib plugin which would accept existing alsa DSD formats and shuffled the bytes for a multichannel PCM-format alsa I2S device. Any native-DSD-capable player (e.g. mpd-dsd) could use it on any multichannel-I2S SBC.

A boom in multichannel hats for RPi5 can be expected, those having a DAC chip with DSD support could even offer native DSD 🙂

I have recently built my own Unraid server, where I am storing my music library (currently as a mirror of the local files on my MacBook Pro). This Unraid backup is itself backed up to BackBlaze B2, and I also am using ZFS. My plan is to:

• Make my Unraid server the source location of my music library, and delete the current music library off of my MacBook, freeing up local space while still being able to access my library as a mounted volume with SMB and play back using Swinsian on my Mac, or via something like Plex on other devices.
  • This means I need a good method of having my current music player (Swinsian) point to the Unraid server as the new location of the music library, while retaining all the current playlists I have set up in Swinsian. My concern is that by changing the location, and therefore having copies of tracks become the new default location, Swinsian won't regard them as the same tracks as the ones it currently has (my local files) in all my playlists. How to ensure the changeover doesn't affect this?
  • Similarly, I DJ and use Rekordbox. I am going to follow this promising guide and tool from u/MixMasterG in order to locate my Rekordbox tracks following the change in location from local storage to Unraid server. If anyone has any experience running their Rekordbox based on a remote, mounted shared folder, I'd be keen to hear any tips or general advice.
• Have a good workflow for the following actions:
  • How I download and sort music:
    • Music from private tracker torrent sites I'm a member of, or Soulseek > some light file name and metadata modifying > sorting these newly downloaded files into folders in my music library (stored on the Unraid server), maybe having some kind of automatic folder sort for "newly downloaded" or "not listened to yet", or something similar if anyone else has any good systems worth sharing.
    • I've heard of a way of setting up automatic downloads of torrent files from trackers that meet certain filtered criteria? No experience with that kind of stuff, would be keen to learn.

If there are any other actions, tools, programs, workflows etc that people have experience of and suggest I look at, that would be cool too. I'm new to the server game and looking to create a complete workflow/music management system.


EDIT:

For clarity r.e. what I want to do with my Swinsian music library:

1. I currently have Swinsian set up to watch a local music folder on my MacBook, which contains my music library.
2. I want to migrate to the mirrored copy of this library, stored on my Unraid server, so that I can delete the local files and free up space on my laptop.
3. If I go and tell Swinsian to stop watching the local folder, and start watching the mounted server folder, and remove the local files from my Swinsian library, surely that's going to result in, well, my current Swinsian library being destroyed, with all the tracks I have set up in all the playlists I've gone disappearing, even though all the files still 100% exist, just remotely in a different location.

So what I want to do is ensure a seamless transition to the server, maintaining the library as I have it now, just switching to having the files stored off the laptop.

Looking forward to my first visit to the Hamvention, is anyone else going or setting up booth? Making my tube list for the flea market. Coming with my wife. I did notice that George of Tubelab is on the vendor list, it would be awesome to meet him! Or any other small businesses here going.

https://hamvention.org/

Hi, could you suggest a spectrum analyzer software for Mac or PC, perhaps for free? I would like to start measuring how my speakers respond in the listening room. If you can suggest me how to do it. Thank you

Thread title borrowed from Nelson Pass.

https://www.diyaudio.com/community/...rtion-killer-circuit.24192/page-5#post-296714

I know that simulations are neither accurate, nor reliable, nor credible, nor are the results achievable in reality, nor [add here what you like]

My simulation results in Microcap12 before 1 month looked like this:

Conditions: Bias 1.5A. Load 8 ohms. Peak power. THD @1kHz

1k: -208dB should translate into 0,000000008 %

I started to become suspicious because THD was already flat until 30W or so...

In the past, when the circuit was not so refined, distortion was always constantly rising with power, starting at -180dB at 10mW power.

Hi, I was thinking about transistors arrays for LTP and current mirrors, etc. ULN2003
They are darlington and most likely not what it should be for that use.
But I found these :
https://eu.mouser.com/new/that-corp...T*MTcxNDgzMTczMi4zLjEuMTcxNDgzMTc5Ni41OS4wLjA.

https://pdf1.alldatasheet.com/datasheet-pdf/view/561341/ETC2/300S14-U.html

Anyone used something similar before?.
- Bruno.

After asking for some feedback on my platform to easily prototype any of my future DIY audio project on Reddit, I started designing/building it and thought I could have a build log in case anyone is interested critiquing/reproduce any of it.

Streamer/Receiver:

• Software/Configuration
  • [✔] APT-x Bluetooth
  • [✔] 96KHz Pipewire Config
  • [✔] I2S Slave config to Main DSP
  • [✔] I2C Bus communication to Main DSP
  • [✔] SPI Connection to OLED screen
• Schematics/PCB Design
  • [95%] Parts selection
  • [✔] I2S Over HDMI Driver
  • [75%] Motherboard
  • [25%] S/PDIF receiver: Still trying to decide between 3 ICs (CS8421, WM8804, DIX9211)
• Soldering/wiring
• Mechanical/CAD
  • [✔] Modeling Rotary Encoder
  • [✔] Modeling OLED Screen

Plate Amp/Digital crossover:

• Software/Configuration
• Schematics/PCB Design
  • [✔] Parts Selection
• Soldering/wiring
• Mechanical/CAD

Hi!

I recently got hold of a power amp almost by mistake and now need a pre-amp. I haven't found anything on the market with the desired functionality and an acceptable price, so i am thinking about building it myself. I have no experience with building amps but I have worked with arduinos and raspis.

The first stage of the build would be the line stage for which I have looked at these components:

• power supply regulator
• a relay source switch for 6 inputs (something like this);
• either a Korg Nutube (+PCB & JFETs) or Wayne's Burning Amp 2018 Linestage;
• haven't decided (something like this NJR MUSES®72320 volume control chip but cheaper);
• a smartknob like the M5 stack dial to control the relay switch and the volume control.

If I get this to work, then I'd like to install an IR remote, a phono stage and a BT dac to the relay switch. Also, I have two speaker zones (also on the power amp) and need to add a switch to the output for A, B, A+B output later on. It's going to be unbalanced.

I know I'm naive, but as far as I can tell, the components are basically readymade and it's a matter of soldering them on a board and connecting them up. I must be missing something, right? Please tell me this won't be as easy as just wiring the parts together.

Suggestions and critisim is much appriciated

I'm going to use a 3-way crossover board (Where I will connect the sub woofer (bass), Mid-ranger (Mid) and the tweeter (tremble)) my question is:
All speakers have exactly 4 Ohms of impedance and I will connect them all to the crossover board, so can I connect a 4 ohm amp to the crossover board?

hello all,

for experimental purposes, i want to reproduce extra low freqencies from 5 to 100 hz or something really near these values.
i know we cant listen 20hz values but it don't tell that frequencies doesn't exist..
exiters? DML?

what do you think as best ways?

Hello everyone 🙂

I've been thinking about building a new subwoofer for my (bedroom) studio.
Being able to 3D print things I was wondering what the theoretically optimal subwoofer design would be.

I guess a flush mounted and sealed design dsp corrected up in to sub to be flat. (At least that my guess)
But even then, having a cube inside as a shape wouldn't be perfect right? Or doesn't it make a difference because the wavelengths are longer than the enclosure?

Apart from this, I can't flush mount. So what would be the best subwoofer possible? A sealed sphere? Or would a simple bass reflex / transmission line be better because it's (probably) flatter up to the rolloff point?

Is it even necessary to think about that?

LG
Johannes

I've got a Dayton Audio SA100 subwoofer plate amplifier.

https://www.daytonaudio.com/product/778/sa100-100w-subwoofer-plate-amplifier

Two questions.

1, Is there a way to increase the sensitivity of the turn on circuit? I use it at work and use bookshelf speakers on my desk meaning the sub is real close to me and for normal listening levels, the sub often won't kick on.

2. The amp best as I can remember since new has had a rather large turn on thump.

Is there a way to fix that?

If I could fix #2, I wouldn't need to worry about #1 as I could turn the auto on to always on and switch it with the power strip that switches the rest of the system on and off.

Also given I use an external active two way crossover and the only way to "disable" the plate amp crossover is to turn it to its highest frequency, is it possible to bypass the crossover?

​

I picked up a pair of well-worn Klipsch KG^2 bookshelf speakers for my office
Waxed the walnut veneer with some Briwax and got ithe cabinets looking great again
Ordered titanium tweeters from Crites speakers

Now I need three capacitors for the crossover network:
4 uF
8 uF
24 uF

I can solder but I know nothing about different types of capacitors and the relative cost-to-value
What is a good value option for these speakers?

I have a Kicker KX2 crossover with the following specs.

High Pass Crossover: 18dB/octave, Variable Frequency (40-300Hz), Low Pass Crossover: 18dB/octave, Optional Low (Line Level) or High (Speaker Level) Stereo Input, Variable Stereo Outputs (5V rms), Signal-to-Noise Ratio: >110dB

How good is the crossover and would it be ok to use in a home stereo system?

SOLD

For sale a very nice ZenMod Iron Pumpkin Single Ended version built in a silver chassis with manual volume and input controls. Wired for 230V. Located in The Netherlands EU and prefer to sell within the EU or perhaps to the UK. Shipping is possible and will pack it up very well.
5 inputs, 2 outputs. This is based on an AVC wound on a Finemet core with a Toshiba JFET buffer. Will add some pictures.
0 to +8dB switchable gain setting. Really neutral and transparent sounding preamp.

Selling due to too many amps and creating budget for another purchase.
ZenMod also has an optional remote kit with TFT display if you would want to add remote control capabilities.

SOLD

In May 2020, I originally opened that thread, but that project lagged sooo much that it is now closed :

https://www.diyaudio.com/community/threads/the-ultimate-kt120.354842/

So I reopen it, my apologies... 🙄

The project is now under construction - I hope to end it before the end of 2023 :





The lateral chassis plate already gives some clue :



More detailed pictures to come, au fur et à mesure... 😉

Hello friends?

Am I crazy?

What would be the issue of driving speakers with an OTL parallel SET of 6s33s?

Thinking about it needs great cooling, a super refined PSU, and the excessive current output...

Found on the web either parallel OR OTL...
What's your take, you tubes experts ? 😀

Let's see if something manageable comes out!

Hi all.
I bought Philips FA960 MKII. After reconnection transformer from 220V to 240 V, recapping, changing voltage regulators in power supply, and putting some new resistors,everything sounds nice and clean, without any noise or hiss.This amp is the first one, what is completely quiet. You don´t even know, if it is turned on or off.
But one thing is very interesting.I measured idle current of STK 3102II (someone replaced the old one 3102 III).
Left side 2,3mV, right side 3,0mV.The manual says it should be 14mV (39mA).So I tried to put R-side very carefully to 6-7 mV while I was touching the cooler on the STK.It was getting too HOT very quickly.So I put it down immediately to 2,3mV like on the left-side. I have tried to adjust 3,6mV on both channels.STK got hotter and the sound has changed (in middle frequencies it was very nice and tight, but treble sounded much sharper....).
So now it is idling at 2,3mV. Amp is without distortion, just slightly warm and the heat sink with output transistors is nearly cold.
Maybe it is normal, that at 6mV it gets so hot, you can´t even touch the cooler of the STK.
.... But then you have to replace STK and all the caps around very often due the heat.
Could someone tell me, is so low idle current normal?
Thank you very much. Jan.

Obsessed to have a great recording Janos Starker Bach suites taken from Master tapes or converted from vinyl in 24 bit wav format files. Do anybody know if a place where this service can be bought exists? Thanxs

Ps annexed the version I look for

I am in the process of finalizing my cabinet design for a 3 way 10" woofer build that will be very similar to hifijim's budget 3 way speakers he has been working. The speakers will be passive, even if it sacrifices some performance away from ideal, because I enjoy the ability to mess with different amps, preamps, DACs, ect. It will use:

Woofer: RS270-4, vented 30L, Fb 32Hz, port length 18cm, port dia 5.5cm
Mid: SB15NBAC30-4, sealed 4L
Tweeter: SB26ADC

I have already used Vituix to simulate most aspects of the design including the baffle diffraction and enclosure volumes/port sizes. However, I am having trouble figuring out the ideal placement of the port based on internal geometry (not distance between room wall and speaker port). The cabinet is quite shallow, not leaving much room between the front baffle internal wall and where internal port entrance is as seen in the images.

I am wondering whether this will be enough room (~1.5 inches from port to wall) or if moving to an elbowed port will be necessary. If anyone has experience/ideas for the internal port clearances or suggestions as to what I can do differently please let me know. Thanks!

"Hello, I'm searching for a MiniDSP OpenDRC-DA8 unit for a diy 4way crossover setup to tinker with. If you happen to have one available that you no longer require, please reach out. Thank you!"

I want to try a new amp with a pair of speakers that are connected to an amp with bare wire. Is it ok to leave the speakers connected to the existing amp, which will be turned off, and connect the new amp with banana plugs.

I'm aiming for around 5k total resistance and around 78dB attenuation in a 47-step, 46-resistor attenuator.

The bottom values are challenging ones. 0.67, 0.12, 0.15, 0.17, 0.2, 0.25, 0.3, 0.32, 0.45, 0.47, 0.62, 0.91, 1.15 Ohms). I can find some, but for others the selection is mostly wirewound and MOX.

Are there any 1/10 to 1/4W metal film resistor kits that focus on small values like these?

I recently upgraded my computer monitor to a koorui monitor and my amplifier I use for my speakers to a TPA3116 however when I plug it into my computer monitor audio output I get a horrible electronic stuttering wirring sound which is horrible for the ears especially when the audio is at a low volume. When I plug in the amp to my phone however, that noise is not there and there is a very soft hiss which I was expecting anyway. How can I fix the horrible noise from my computer monitor?

Hello. My no-name amplifier burn out by some reason, but it was not quite good, as well was made with so-so transistors ( TIP41C ), so I wish to get a bit better one and with a higher output.
I stumbled upon these 2 which seems good choices, at least by looking at similar amplifiers. I aim highest quality possible for like 40-50 bucks.
Please help me decide ( if u have something else on mind please poste it as well - all suggestions is welcome )
So :
https://www.ebay.com/itm/3256821122...-8e35-e65a121c59e3|iid:1|vlpname:vlp_homepage

or
https://www.ebay.com/itm/1561016332...-8e35-e65a121c59e3|iid:1|vlpname:vlp_homepage

Thank You in advance guys.

Very strange little beast....

https://www.wavecor.com/html/tw045wa01.html

I know, I know. This should be a topic that is well covered. Except I have looked and although there are references to surround use for speakers, e.g. the Fountek FE85 powered Quark, I cannot seem to find a thread that suggests / discusses a rather good, affordable HT setup.

I am tempted by Paul Carmody's Overnight Sensation based solution. Misc Home Theater at https://sites.google.com/site/undefinition/home-theater-speakers
I like the Voxel Sub - or at least I expect to because I have built an Isetta and I'm just blown away by what the Tang Band W5-1138 can do!
He has designed a centre channel that is usefully dinky, using the Hivi B3N mid units and T20 tweeter.
Then it is a pair of OS MTMs for the main front L+R and a pair of OS TMs for the rear pair.
This seems like a nifty and affordable setup and I would like to build them all using the T20 tweeter so they all look and voice the same. I also like the idea of gently but securely screwing a tweeter down rather than hammering it into a hole a la Dayton! However I am having difficulty finding the T20 crossover designs for the MTM and TM. The only link for them is to the Meniscus site which is now defunct.

I already have a pair of C-Notes and like them. They are in my computer room / office system.
I would happily build some more as rears, even though they are more expensive than the OSs. There is a center channel design for them too, although it is a bit big for my needs, but what to do about the main fronts? More C-Note MTs and just turn up the bass? Not the preferred option.

Any other suggestions for an affordable DIY surround speaker package?

Making my own boxes is not a problem. I have tools that produce sawdust really fast!

Can anyone ID the tube and the possible application of this breadboard setup being sold on eBay? The same seller seems to be selling some crazy PS parts as well.

Breadboard https://www.ebay.com/itm/196323920597

Power supply component? https://www.ebay.com/itm/364772566373

** The Backstory **

Before I can get to my questions, I have to give you some back story first.

Many years ago, I used to attend the yearly HAM Fest in my area. Every year there were hundreds of people selling literally thousands of nearly identical capacitors. Each capacitor was the size of a Tall Boy can of beer. The going price for these capacitors (from any vendor) was $1.

I've always assumed the capacitors originally came from the phone or power company. Probably because 1) there were so many of them, 2) there were so many people selling them, and 3) they were all the same size, shape, and being sold for (or, basically being giving away for) the price of $1.

Other than the size, shape and cost of these capacitors, the only other identifying information I remember was the number 470. I can’t tell you if that was the rated Voltage, the number u-Farads, or the number of corn flakes in a box of Wheaties.

Years later - when car stereo power capacitors hit the market costing multi $100’s a piece – I started to form a thought...



** Assumptions **

For the purposes of this discussion assume there's a car amp involved, and the car amp in question is 1000 Watts.

Also, let’s assume that the value of 470 was referring to the cap's maximum voltage rating of 470V (which I think was the case).

And finally, remember, I don’t know the actual value of the capacitance, so feel free to use a value you think fits..



** The Questions **

Question 1: With a rating of 470v, could these caps be repurposed to supply base power for the 1000w if they were conventionally connected between the car battery and the power amp supply voltage input?

Question 2: Assuming the car amp is 1000w and has a reasonably realistic rail voltage for the CMOS output stage of, say 200v (feel free to substitute a better value here as well). Could the caps described above be repurposed to supply oomph to the amp if they were wired directly between the power rail and ground?

Question3: In question 2, how much would having a second 200V plus DC power supply connected directly to the power rail help the sound?


Thanks for reading all this !!

Hi, I'm working on a 2 in 6 out crossover for my audio system. I have a wondom apm2 with 4 dacs + 4 i2s out, so I had to add an external dac as well (https://www.audiophonics.fr/en/dac-and-interface-modules/dac-pcm5102mk-i2s-p-10551.html).

Tried setting up a 500hz test signal on all outputs in Sigma Studio and got this. dac{0,1,2,3} look like the purple while dig{0,1} look like the green.

Any clues why this is?

I just ordered a pair of 8fe400, couldn't resist at 22euro each.

There appears to be pretty much zero on the net about them.
FS of 100hz is going to limit they're use in a 2 way, but 200-2k looks very smooth and 95db+ sensitivity would work well with the celestion 1-1746 and Pyle 612 I've had in the loft unused after getting caught up the the econowave excitement.

Probably have some celestion 15's I could use to make a 3 way too.

Am I missing something? Are they lemons?

Enzo

Hi

I know this has an exremely small chance of being fullfilled, but I have been able to acquire a very nice, late model Najda, and would like to add the expansion card.
All help/leads appreciated.
Thanks

I searched on s-manuals.com for C3PGB but didn't find it. S-manuals.com had a lot of C3's I ask if any knows what C3PGB is a npn, pnp or ?
It's off of a MTX THUNDER 6500D.

Thanks for any help.

Hi after 50 years it’s time to start unloading some equipment. I have two 19 inch racks that are 5’8” tall. The racks are free but must be picked up. I am located about 30 miles east of Los Angeles. Note: the racks are Altec green as they came from them. My only request is that they not be sold as scrap.
Thanks,
Ken

Hi time to unload 50 years of audio equipment. I have two dual Burson Opamps, that were purchased probably 9 years ago for a PC sound card but didn’t have room on sound card to install. Asking $40 for each or $75 plus five dollars shipping US only please.
Thanks,
Ken

Hi time to start in loading 50 years of audio equipment. Have an almost full roll of lead free Wonder Solder. I am just asking that member pay for postage, US only please. Solder has been spoken for.
Thanks,
Ken

I have two dead Allen and Heath Zed6 mixers.

Mixer 1 is a zed6fx
Mixer 2 is a zed6

I was listening to music on mixer 1 when it lost power. No lights. Switched off and on. Nothing. Dead.

I checked continuity of the mains cable and fuse and checked mains was coming out of the mains cable into the 3-pin socket on the mixer.

I opened the mixer followed the volts to an internal pcb mounted fuse and ordered a replacement.

I replaced the internal fuse.

Switched the mixer on. Nothing. No lights. Dead.

I swapped it with mixer 2.

For several weekends, I would listen to music through it for a couple of hours until a week ago it lost power. Exactly the same as the first mixer1.

What is killing my mixers?
How do I check this?
How do I fix this?
Does anyone have a clear pdf of the process circuit diagram?

For mounting of power MOSFET on heatsink of Aleph 5 clone on 2 separate heatsink, is there any preference to:

1) mount Q6 - Q8 on a heat sink, and Q18 - Q20 on another heat sink; or

2) mount Q6, Q7, Q18, Q19 on one heatsink, and the rest on the other.

I am asking this from the point of thermal consistency, and if there are other considerations such as interference etc.

Thank you

Verry good speaker binding post from German hiend conectors maker.Pkus one pair of ther verry good rca conectors.Used but full functional .Plese look on the pictures.Price 150 euro including shipping inside EU!

Hello again!
Being thinking too much, I ask myself how to come by with troubles with EMI etc.

Firstly, I had to tuck my UFSP phono pre as far away as possible to get it out of the range of the other trannies (preamp, poweramp, computer). Would it help and be sensible to put the boards into a shielding case of iron inside the aluminium-chassis?

And secondly, I am currently working on a tight build (the holy grail , mine is at #548), where the PSU will be stacked and placed inside the amp, and try to make up a shielding solution… so I’m thinking about building something like a shielding-case inside the chassis.
Should the rectifier be included in the shield? (Would this help?)
Same with the CRC block…

I am building a 300B amp with a CCS on the driver tube and the Coleman V-9 regulators for the 300Bs. I would like to be able to adjust these from outside the chassis instead of the small pots on the circuit boards. Are there any pitfalls in using 1KΩ (for the CCS) and 500Ω pots (for the V-9 regs)mounted a few inches away from the circuit boards?

Hello! I'm restoring and upgrading an old pair of 3-way speakers. I decided to make a crossover upgrade as well since I was at it. The old one didn't sound very well. I measured the drivers and loaded the data on Xsim.

It's an old pair of Namco NSU-770 (made by Panasonic in the 70s I guess...)
It's a 12" woofer paper woofer, 2,5" paper dome midrange, 1" aluminum tweeter.

This is my try at it but it's my first time doing a 3-way.

The FR and impedance graph look pretty okay to me but when I was setting the delay the simulated curve didn't overlap perfectly with the measured one. I did my best to match as closely as possible the measured tweeter + midrange response with the simulated one.

The woofer's FR looks pretty odd, there's a big hole at around 700Hz. I guess I'll have to live with this. The phase seems okay, reversing the midrange compared to how it's now leads to a weird FR.

Do you think this design can be improved in any way?

Project files are attached.

Thank you!

Hello from Hamburg

Almost 60 years old, but not completely deaf yet...

I use a small Asus notebook with Daphile as operating system via USB to my Nubert X-8000

I love it!

My musical interests lie between Archive and ZZ-Top

SOLD

Selling an immaculate Focusrite Scarlett 18i8 (2nd gen) audio interface; includes original packaging and accessories

• 2x XLR / TRS / TS combo (mic / line / inst) inputs
• 2x XLR / TRS combo (mic / line) inputs
• 4x TRS line inputs
• 2x TRS line outputs
• ADAT input (8ch @ 44.1/48, 4ch @ 88.2/96)
• S/PDIF input & output
• 2x headphone outputs

Original power supply and USB cable included.

Would prefer to ship within EU (25eu); open to shipping elsewhere as well, pending checking costs - customs and any other fees are the buyer's responsibility.

Looking to get ~220eu 200eu, but i'm open to offers 👍

Payment via Paypal, Mobilepay or bank transfer.

I've just purchased a pair of Wharfdale Progamme 50 for my desktop 2.1 system. (Not arrived yet). Does anybody have any experience of these things?
Wharfedale claim a sensitivity of 96dB - that seems a lot.

Guys is this really a thing, can one slightly adjust pitch by choosing a different belt thickness? Thanks.

I have a pair of W8 2145 lying around and wonder what to do with them.

Open baffle is out of the question and I already have a pair of BIBs doing their job wonderfully as "allround speakers" with W8 1772's in them.
Thanks to @Scottmoose I also already have a pair of desktop TL speakers. So all my audio-needs are taken care of.

Just for the fun of it, I thought about maybe building "very small" desktop bass-reflex speakers so I could have the 8" speakers blasting into my face more or less directly.
What else could bedone? 😀

Good morning!

Does anyone use LS7 / CV1660?

Does anyone have access to the characteristics?

I am going to build a stock Darling amplifier, is the Edcor XPWR146, 200 volt secondary @250ma or the Hammond 269AAX, 200 volts @ 250ma the correct transformers to use?

Hi,
Hope you're well.

I received this amp (image attached) as a gift a few years ago and it's worked like a charm.
However recently the sound started stuttering when connecting to my computer, but not with other devices. I tried these steps but none helped: Login to view embedded media Now my computer is no longer connecting to it (image attached).
The last time it did connect, it was asking for a password but I don't remember it.
I've tried all the usual steps to reset drivers, uninstall reinstall etc from the computer side, but nothing works.
I've clicked the reset button on the amp and that didn't do anything.

Any advice would be really appreciated.
Kind regards,
Yogi

I just came across the system 1 from nakamichi, I must say I quite like it.

As stated in the title, too bad nobody seems to go down this rabbit-hole anymore.

I mean, that’s techy product design, and the chassis‘ concepts are quite smart, allowing both an on-desk or in-rack placemt without the huge depth of yesterday’s gear. (Ok, nowadays it’s all pocket-sized but hey!)

Quality has a price , first the transducers in all their glory :

https://www.kartesian-acoustic.com/copie-de-monitoring-studio

Some graphs to seperate the good from the bad and ugly (danish rubber scandalettes) :

https://www.kartesian-acoustic.com/copie-de-vki

Study Them Well Or Go To Hell 🙂


ps .. anything you need for a good life : Login to view embedded media

Does anyone have either 2 genuine LM3875 or 3886 chips?

I'm thinking of putting a power amp or two in an SWR Henry the 8x8 cab (8x8" at 32 ohms each). This one seems like a good choice. I figured I'd run the cab off of two amps (or a stereo board) with each driving an 8 ohm (4 speaker) load.

Is there a good ready to use board on ebay?

Yesterday I received a great condition Adcom GDA-700 DAC. My first experience with the PCM1702 chip, I like it! I have a Audio-GD R-1 NOS already and while it is pretty amazing, I've never felt like I completely vibed with it, mainly because the sound stage is so very in my face all the time. Now with the Adcom, I am hearing pretty much all the same detail but with a much more dispersed and pushed back soundstage. And for about third of the price, this is a win for me.

So I figure now that I have it, it would be worth it to tinker with OP amps and replace some parts since this guy is from 1995 😎.

The tools I own already:

• Soldering iron
• Good Rosin solder, solder wick
• Decent Multimeter w/ clip and point leads
• Cheap pcb holder

I should probably get a chip puller, can't think of anything else tool wise. I have good experience I believe since I have completed a BHC amp and various diy cables.

I figure the sound quality can only go up from here. Problem is I don't know/don't really understand how to choose replacement OP amps. I get the general principle but frying my new dac would really suck. I did some digging and found this post for modern OPA alternatives: https://www.diyaudio.com/community/threads/adcom-opamp-semiconductor-replacements.339904/

The ones in the GDA-700 are ADCOM 6AA 9439. According to the chart I can use OPA604 or AD711. I would love to use some sparkos SS3601 OPAs but I need to know if they aren't compatible.

Other than the OPAs, is it safe for me to order all new caps with matching uf/V ratings as the ones already installed? A quick search led me to these caps:

https://partsconnexion.com/products/elna-capacitor-10uf-35vdc-roa?_pos=1&_sid=c38316f85&_ss=r

The only schematic I found was pretty rough but still legible:

https://akdatabase.org/AKview/displayimage.php?album=20&pos=6

This is a big step for me but it's got me pretty stoked! Any and all advice is greatly welcome. Thank you for reading my first post here.

Photos below

I've been attempting to learn Xsim over the last several nights trying to work out a crossover for an upcoming project. I think I have a beginner grasp of what to do in regard to leveling out the frequency response, but I feel lost when it comes to keeping the phase in check. I also am unsure what my goal is for the impedance chart so any pointers there would also be of great help. Please let me know if I'm massively screwing something up with this 🙂 I have attached screenshots of the charts and wiring diagram and the project file.

I was able to pick a set, Rockford Fosgate RFP-2000 ( Hafler JF2000 ) and the matching preamp the RF-200 for very little money, very good quality.

Can anyone comment on the design of the amp ?
32 mosfet transistors
2 42000uf 80V power capacitors
a few 5532 op amp in the motherboard, all Texas instruments

The only problem so far with the amp, is one side gets hotter than the other one.
Since the amp has so many output transistors, how do I know that all of them are working fine ?
Any idea the bias number for this amp ?

I wanted to share some designs that I have been working on towards a dedicated standalone chassis for the FFAxxxx series of amp modules

First up is a mounting plate for the FFA001 module. This one is designed to be 3D printed and can be fitted inside a chassis or into active speakers, including instrument amps

Single fan


Dual opposed fans


Fasteners are M3 with the thread printed into the mounting holes. For instrument amps, M3 threaded rods are needed or long bolts if you can find them. The module is fitted inverted with the PCB side up. A 5mm standoff should be placed over the holes, and this will hold the module down and provide a receptacle for a matching metal sheet as screening cover. This isolates the heatsink which is elec active and protects the module entirely

Still double minded about the standoffs. I might do a version without them and instead use 50mm metal ones. This one is for tomorrow to solve

The back of the mounting plate inlays the fans and has allocation for air filters. Mounted inside a narrow chassis, the dual fan version is optimised for air flow around the module components

This is my priority project, so will soon upload the STLs for more parts such as custom speaker terminals and panel inlays, as well as a chassis that makes provision for a tube linestage for this class D module. Hope the community finds the plate useful and guys, share your custom creations here too

Hi,

I need the service manual for the DBX 4 BX…I would like to recap mine. and do a great oberhaul

Thanks 🙂

Hi Folks,
I was working on a project and really needed to see a copy of the original Thiele-Small papers on modeling dynamic speaker drivers from 1961 (Thiele) and 1971 (Small). These were not easy to find in a free format as they are typically cited as J. Acoust. Engr. Soc. papers. But I eventually found them. Very nicely written and amazing how they are still used to this day. A lot of similarity with the solution to the classic forced damped harmonic oscillator equation of motion.



Anyhow, it gave me an idea that once I find stuff, and if you guys find anything of use, let's post here for others to share.

PDF's:

Here is the one by Thiele from 1961:
https://diyaudioprojects.com/Technical/Papers/Loudspeakers-in-Vented-Boxes-Part-I.pdf

Here is where I found a scanned copy of the classic 1971 paper by Small:
https://diyaudioprojects.com/Technical/Papers/Direct-Radiator-Loudspeaker-System-Analysis.pdf

A nice treatment of the equations from above by engineers at ScanSpeak and put into MathCad format:
https://www.scan-speak.dk/datasheet/tech/Scan-Speak_Technote01_TS-measurement.pdf

How to use LTspice to sim T-S:
https://www.micka.de/en/download/spice-tsp_en.pdf

Threads / Websites:

There is a thread in Multiway on using LTSpice to model Thiele-Small parameters for speakers:
https://www.diyaudio.com/community/threads/thiele-small-reloaded-with-ltspiceiv.166467/

Videos:

Nice tutorial on analyzing stability of feedback circuits using LTSpice:
Login to view embedded media
How to measure open loop gain in LTSpice:
Login to view embedded media
Perhaps the BEST lecture I have ever seen on solving damped harmonic oscillators - by Prof Walter Lewin (MIT):
Login to view embedded media
Prof Steve Brunton (U of Wash) also gives great explanations on damped harmonic oscillators (4 ways to solve):
Login to view embedded media Login to view embedded media

Hi, I'm a long time lurker and now in a position to build stuff, starting with a Sapphire Headphone Amp. Nice to be here...

Hi everyone. Today im fixing a JL audio jx500/1d amp. Someone try to fix It before me so It comes with fqp12p20 mosfet at the PS, i think maybe need aot460 like others JL amps.
On the other side the 2 diodes AND the 2 output mosfets aré missing.

Anyone have the parts numbers? I need to buy all, the 4 PS mosfets, the 2 rectifiers AND the 2 output mosfets.

Thanks

Dear fellow builders,
I am struggling to describe the differences between my ACP+ and Wayne's Linestage Preamp. Using the same Mark Johnson VRDN LPS for both of them. I prefer the ACP+ for experimental electronic music but I am not sure why.. maybe because it has a deeper soundstage and the sounds are "flying" closer towards myself? Or maybe the ACP+ has slightly thicker bass. For acoustic music I prefer Wayne's Linestage. Does anyone have experienced both preamps and could help me with describing the differences? Thank you very much!

Kind regards,
Johannes

I've recently heard a pair of speakers at an audio show named the Endeavor E3 from VonShweikert, and despite being a smaller pair of 3 way floor standing speakers, sounded phenomenal. Perhaps the best I've heard considering the size. Being an avid engineering enthusiast, I figured to try and de cypher some neat design choices that was used when designing this speaker, and I thought to maybe get some expert input from you all as well.
Two models available: standard and special edition.
Standard:
Dayton audio reference woofer RS180
Hivi L6 kevlar woofer
Scan Speak R2604 ring radiator tweeter

Special edition:
Dayton audio reference woofer RS180
Hivi L6 kevlar woofer
Scan Speak D3004 beryllium tweeter
Rear mounted Fountek Cd3.0 ribbon tweeter

Crossovers:
modified 4th-order linkwitz-riley with zobel conjugates to ensure correct phase and time alignment-with extremely wide horizontal and vertical off axis accuracy.
Frequency Response: 29Hz to 22kHz (+/-2dB)
Weight: 95 lbs per cabinet
Dimensions: 44" x 9" x 15" (HxWxD) Tapers down to 5" width at the back.

Enclosure design:
Here's where it gets creative. The bass is said to be loaded in a 4th order Butterworth modified "tuned" aperiodic vent design, critically damped to Q=0.7.
The midrange is said to be loaded in a tapered transmission line to avoid standing waves and rear reflections to ensure accurate midrange.
Total cabinet thickness: 2.75"

I'm genuinely interested in learning how such bass is achieved in such a small design. Modeling these drivers in software using just a normal vent means the enclosure must be 2-3 times the volume in order to achieve a -3 of 28hz.

Hi,

I was using Behringer UCA222 for frequency measurement, but recently learnt that it has poor channel separation. I verified by using a signal on left channel and connecting and amlifier/speaker on the right channel. I could hear the test signal from right channel😕, even though it was faint.

So, what better USB sound card do you guys suggest for frequency measurement?

Thanks in advance,
Warm Regards,
WA

I notice most tube gear has unbalanced connections and the one piece of tube gear I tested that did have balanced jacks in addition to unbalanced, performed much better better using the RCA/unbalanced. I noticed when I opened it up, the XLR jacks were connected to some small transformers which I assume are what converted them to "normal" signals for the pre-amp board.

I haven't really studied this in depth yet, but my limited understand is most tube gear is not natively easily adaptable to balanced cables and use these types of transformers to convert that type of balanced signal into something they can process? I know I have rarely seen any tube schematics showing balanced connections.

Thanks in advance!

NOS Minx Xi from a dealer stock. Only head unit without accessories- (no USB antenna, remote, BT ). I checked basic amp, dac functions and it works fine. It won't connect to internet since it hasn't been updated and the system version is too old to bridge the gap with last issued software update. Cambridge Audio service recommended update via stick which would necessitate sending it to service dep. Any of you Diy mavens probably can make it work without the factory help.
I have no use for it and all the women in the house are too stupid to operate it even if I gifted it to one. Factory box and basic manual included and protective film on the face plate still present. $250
I will post pictures shortly

I have desoldered components off boards for about 4 years now however I am currently battling something I have never been able to do with my Hakko 808 or a soldering iron and that is desolder a component off a double sided board
I can get the solder off the opposite side of the component but the solder on the component solder is unaffected
I am trying to remove most of the through the hole caps

Is there a secret I dont know about and I hope it doesnt involve using a soldering iron and the hakko at the same time

I am in a situation where I have to built a very slim low profile picture frame speakers. It has to go on the wall, can’t go in wall. I found a speaker that checks all the boxes https://www.morelhifi.com/en/products/custom-integration/soundwall-30/soundwall-powerslim-series-42

I have a few dead ends I am hoping someone can clear up for me.

1. I am building a frame out of 1/2” high density MDF measuring H16” x W28” x D1.75”, which equates to .18 cu/ft

2. According to the speaker manufacturer the speaker must have .45 cu/ft

3. Can I built a port into a frame that can compensate for the difference of .27 cu/ft

4. The manufacturer also suggested stuffing the cabinet cavity with “pillow stuffing”. Will that help in any way?

Any suggestions are greatly appreciated.

Hi everyone.
I recently purchased a used Whammy headphone amplifier.
Works well .
The power transformer however is a 15v+15v not the expected 18v+18v.
Whoever made it used 3.3ohm RC filter resistors.
Can it be okay like this?
Grazie

Hi all,
I recently purchased a pair of Fostex T825 super tweeters, probably about 40 years old (originally from Fostex Laboratory series LS/3 monitors).
After a quick sweep the measurements lead me to believe one is faulty.

Does the lower trace show signs of a bad diaphragm? Or diaphragm not aligned/seated properly?
One sweep is with 4.7uF cap and another with 1.0uF cap.
Both measure 6.7ohms
Thankfully, the seller is willing to refund if I'm not satisfied.
Looking for some opinions before I bring them back.

Serial numbers are almost consecutive (11156, 11158).

Hello everyone,
I have a Harman kardon avr 265 amplifier. I have a problem with obvious low sound on the left channel. There is no such problem on any of the other channels, only the left channel.
Recently, when I first turn on the device, the opening screen appears and freezes. When I press any button, it goes into stand-by mode and does not turn on. When I unplug it, plug it in and turn the device on again, it turns on and works without any problems.
Here's what I've tried so far regarding the sound problem in the left channel:
-different speakers. It didn't work.
-different cable. It didn't work.
-I tested it from different analog and digital inputs, it didn't work.
What do you think is the problem?
Thanks in advance to everyone who will help.

Hi!

I'm building a Doctor Amp princeton kit and after building it completely I can't make it to work properly. The only sound I get out of the amp is a loud noise.

I've checked if I had positive feedback but the noise is still there after reversing primaries on the output transformer or removing the feedback wire.
This is the noise I'm getting Amp Noise

Any advice of what should I checked? any mistake I should have made? Any bad component?

Thanks!!!

Edit Dec 5. 2020: the GB is now taking preorders in my shop. I am including a free BTSB PCB with each order.

XRK RTR TPA3255 Reference class D Amp GB2

RTR TPA3255 Reference Class D amplifier | Etsy

This is the GB number 2 thread for the ready to run (RTR) TPA3255 reference Class D amp from this thread:
TPA3255 Reference Design Class D Amp GB



The thread has a lot of details on the development process and build question and answers. A GB interest list will just get buried and lost in it so I decided to make a new thread as there seems to be some renewed interest now that Redjr has just released his masterpiece build using this amp. I have already received several requests for more RTR amps.

To make this viable for a manufactured amp from a California based assembly house, I will need a commitment for at least 20 amps from folks here. I will pledge to buy another dozen amps and we then get these professionally made using a pick and place machine with a genuine Mouser BOM.

As before, the default amp will be balanced input stereo BTL output. We now have the BTSB Buffer board to go with it which will provide the necessary conversion from SE inputs and gain to drive this amp effectively.

BTSB Buffer - SE/Bal to SE/Bal Buffer GB

The amp will be manufactured using 2mm thick pcb’s and 2oz copper and ENIG finish. Amp modules will be fully tested and come with a set of Molex connectors for audio in, speaker out, and PSU in. Pricing of the amp will be $277 each. The lead time may be up to 3 months, although I think it will go much faster this time since it is a second run and we have the kinks all worked out.

Edit Aug. 21, 2020: Special Promotion - Free BTSB Buffer PCB (TH or SMT) with your order of the RTR amp. A $23 value that allows this amp to be used with any source.

Please put your name, number of boards, and country down on the list below. Once we have 20, I will put a preorder listing on my shop for you to purchase.

Thanks,
X


Interest List:

Name / number of amps / country
____________________________

JohnDoe / 2 amps / USA

The first tweeters I bought were these as I thought they were quite benign for a beginner to work with. Great tweeter. I still have the first pair and I bought this 2nd pair thinking I'd use them for another project but it never happend (see my other gear for sale...I have eyes bigger than my belly when it comes to buying drivers!)

New from THLP in the original packaging.
£50 plus post