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Fancy Interconnects? How about a potato, or even mud?

OK, we've all heard or read the sales pitch for interconnects of fancy materials and geometries, I've got them all beat.

Did you know that you can pass a line level audio signal thru a banana? How about a sweet potato or even a bucket of mud? You can, quite easily. No joke, it really works. You can even stick two wires in the dirt in the back garden and pass an audio signal thru the dirt.

I spent this afternoon doing just that, and making recordings of it. This is no April Fool joke, it really works. If any of you are interested in what it sounds like, you can do it yourself, or I can post samples here.

You'd be surprised at what a musical signal sent thru a banana, a potato or a bucket of mud sounds like. Cyro that, cable guys! 😀

Anyone care to hear it? Anyone care to guess what it sounds like?

Resistor power dissipation

Hi all,
I'd like to know if maximum power dissipation of a resistor sums up if using multiple resistors in parallel as opposed to a single higher powered resistor? Granted we use the same values for all the resistors that are connected in parallel.

Let's say we tie a pair of 5W 10k resistors together for a total of 5k, do we end up with the same heat/power dissipation of a 10W resistor, or is the 10W going to run cooler by having a larger body and probably a different gauge wire inside it?

First time with a question on Third-order crossover

Is there any calculator or formula for reverse calculating results of “third-order” crossover such as crossover frequency and Q-factor from component values?

In second-order crossover, there are two formulas which are resonance (f = 1/(2 x Pi x sqrt(L x C)) and Q-factor (Q = sqrt(R^2 x L/C)) formulas so that we can definitely reverse calculating crossover frequency and Q from any given L and C values.

How about third-order crossovers?

Please do not suggest me to go using Xsim or VituixCAD because I’d like to know the simple and quick methods to approximately estimate the circuit.

Luxman L-550 AX voltage change 100v to 120v

I have a Luxman L550AX that is a Japanese spec 100v version. I am using an external transformer but I want to move the internal jumpers to set it up for 120v 60hz.

I opened it up expecting to see something like the first picture (A Musical Fidelity piece that I am working on) where I can just move the jumper.

But then I opened the Chassis, it is much more crowded and the power inlet has no easily accessible jumpers. It looks like the power supply is under the grey shield marked in the picture.

Does anyone know how to change the input voltage on a Luxman L-550 AX? I am assuming that it is a simple jumper change and that the jumpers are located below the grey shield, but I do not have a schematic and I don't want to take this apart if I don't know what I have to change ahead of time.

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Setting up a Fusion Amp 3-way Step-by-Step

Hello people!
It seems that many people are having trouble getting a Hypex FusionAmp set up properly. Others simply would like a clear application note.
As I did not seem to have had any issues with my method, I will share here what I did in a step-by-step instruction as an application note for a 3-way setup!

First off, I have nothing to do with Hypex. I do not know anything other than what can be found in the HFD help file or on their webpage. As such, this is no official guide, so use at your own risk! 🙂

Before we get started. Here are some useful links:
HFD software:
https://www.diyclassd.com/img/upload/doc/software/hfd/Software/HFD_4.8.zip
HFD manual:
https://www.diyclassd.com/img/upload/doc/software/hfd/Documentation/HFD_4.8_Help.pdf
FusionAmp manual:
https://www.diyclassd.com/img/upload/doc/plate_amp/FusionManual.pdf
NC100HF datasheet:
https://www.hypex.nl/img/upload/doc/ncore_mp/nc100hf/Documentation/NC100HF_03xx.pdf
NC122MP datasheet:
https://www.hypex.nl/img/upload/doc/ncore_mp/nc122mp/Documentation/NC122MP_02xx.pdf
NC252MP datasheet:
https://www.hypex.nl/img/upload/doc/ncore_mp/nc252mp/Documentation/NC252MP_02xx.pdf


The way I used my FA123 is for a classic three-way setup. My gain values and delay values are most likely very different from yours as I use a midrange driver that is significantly more efficient than my tweeter and I use side firing ineffective subwoofers sitting far behind my mid and tweeter. This is however, one of the odd combinations that is possible with a DSP plate amp as the Fusion series!!! 😀
Fore more info on my build see this thread: Small active 3-way floor stander with a punch

I have a Yamaha Bluetooth receiver with a digital S/PDIF output. This is connected to the S/PDIF input on the master module. My TV is connected to the optical input. If I want high-resolution music, I connect my PC to the TV via HDMI which then sends it to the FusionAmp over the optical connection. For background music, I use the Bluetooth receiver via phone or PC.
I use the auto off and signal detection functions. In firmware version 1.3, these work great. I connect my PC to the TV or Bluetooth and start playing music and in roughly 6 seconds, I have music. In that time the module wakes up and select the input that is used.
Very girlfriend friendly 😛

The following posts will be a step-by-step guide on how I setup my FusionAmp and designed a crossover with it. It may not be the one and only way, but it works 🙂


Text underlined like this are steps you have to take.
The rest is just information and explanation like this.

Hifi Selbstbau DK-SAT 1 kit

For sale monitor kit speaker kit from HiFi Selbstbau Germany with Eton Bassmid and Harwood AM-20 airmotion tweeter.I have all the dokumention to build the enlosure and schematic for crossover.I also have all parts for crossover if someone will to buy this.There are Jantzen SuperiorZ caps,Mundorf copper foil coils,intertechnik air coils and Jantzen superes resistors.Price only for 2x eton 5-880 bassmid and Harwood AM20 air-motion tweeter is 150 euro plus shipping,with all crossover parts included is 250 euro plus shipping.

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Kemet capacitors

Some verry good caps lije new condition,some are unused some are used for only a month or so.Plese look on picture for data.Price for lot is 150 euro including shipping inside EU!This are big and havy caps verry good for class A current amps,becouse this caps can handle lot of amps.More info on contact.

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Lining a Eland cabinet for an Alpair 10.3

I am gearing up to build a two ELAND cabinets using MarkAudio Alpair 10.3 drivers (already purchased).
My question regards lining ("lagging") the cabinet with Ultratouch insulation.

The first schematic from DIYaudio states and shows that all surfaces should lined
https://www.diyaudio.com/community/...audio-fostex-tb-dayton-seas-etc.323051/page-3

While the schematic posted on MarkAudio.com states and shows that one of the sides should NOT be lined.
https://www.markaudio.com/eland-alpair-10-3-compact-mltl/

The first depiction is attributed to Scott and the second is not (or forgotten). Otherwise the dimensions appear similar. So my question is obvious, do I line all surfaces or not?

Before someone responds: "try it both ways ....", the manner construction does not allow for a removable back in order to "experiment".

Thanks, -Tom

Accessing Pot to Clean on Cambridge A&R A60

Looking to thoroughly clean a slightly noisy pot on the cambridge A&R A60. I have been using contact cleaner and trying to put it down the small holes in the casing, but don't, think it is penetrating deep enough. To access the Volume pot and give it a thorough clean, do i need to just remove these circular metal casings, using small pliers to bend back the metal attachments? Please see the photo for reference. Thanks!!

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PCBs for Samuel Groner's Low Noise Laboratory Grade Measurement Amplifier

UPDATE: all board have been sold. Thank you!

For sale are PCBs for Samuel Groner's Low Noise Laboratory Grade Measurement Amplifier as published in the Linear Audio Vol.3.

Quoting the author:
"[The preamplifier] is particularly aimed at noise measurement tasks. Its design features a single-ended JFET input stage, an active drain load for good power supply rejection and a novel input AC coupling network which attains, together with a DC servo, a second-order response. The achieved performance includes an equivalent input voltage noise density of 390 pV/rtHz (1 kHz) and 500 pV/rtHz (10 Hz), a frequency response of ±0.1 dB (10 Hz–100 kHz), a power supply rejection of at least 95 dB (10 Hz–100 kHz) and a quiescent current of just 17 mA. Detailed theoretical background on low noise design along with concise construction and application notes are included [in the article].

Samuel has kindly made gerber files for the board available on his website, and I ordered a board for myself. However, there was a minimum batch, so I am offering here the surplus boards.

The BOM can be found at Samuel's web site. Should you need the schematic, I'd recommend buying Samuel's article from Linear Audio - it is only EUR 2.99 and is immediately downloadable.

I am asking for $30 per board with free USPS First Class shipping to the continental U.S. For the rest of the world, add $12 for shipping. Payments via PayPal.

Please PM me if interested.

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For Sale Genalex Gold Lion 6922/E88CC Tubes

I bought these tubes recently for some tube rolling

Fantastic little tubes, but unfortunately due to high frequency damage to my ears, I have to sell them on.

Been used for approx 170 hours (150 hours burn in and then some listening)

These are a matched pair

UK sale only price is £105, eBay link is below for safe purchase or pick up from Glasgow (UK)

https://www.ebay.co.uk/itm/267042124795

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Tube Hoarder Coming out of The Closet.

I am relatively new to the hobby. My son took up guitar, so I've finally had a chance to start messing with tubes. I've completed a 6G2 princeton, and am troubleshooting my latest 6G16 Vibroverb build. I also have a very original Sherwood 8000 MkIV that at the very least will require a recap?

Thanks in advance for the knowledge alreay shared here, and for the willingness to help out Newbs.

- Murray

DIY portable bluetooth speaker

Hi All!

After spending a lot of time trying to choose which bluetooth speaker to buy, I got the idea that they were very overpriced, so I decided to build my own. I've never done a project like this before, so I'm a complete novice at it, but I like the idea of building my own speaker. At the moment I have the following plan:
Speakers:
Dayton Audio RS125-4 (5 inch , 30W, 65-5,400Hz)
Dayton Audio DC28F-4 (1 inch, 40W, 3,000-20,000Hz)
Crossover: Dayton Audio XO2W-2,5K
Amplifier: Sure Electronics AA-JA31213 1 x 60 Watt Class D (I'm least sure about this choice because this amp has 24V in its specification, but there is for example a TPA3116D 2x50W that operates between 5-24V)

I plan to mount these in an 18mm MDF enclosure of approximately 300x200x250mm with a 50mm diameter bass reflex tube.
What do you think so far about this setup?
How do I exactly tune the enclosure dimensions and how does this match the length of the reflex tube?
What battery is needed for this setup?

Thank You!

Bluesound Powernode N180 PSU failure

Dear Forum,

Trying to repair a Powernode N180 with power failure. This is an early generation (second?) of the Bluesound Powernode.

The problem manifests itself by the infamous “red Play/Pause” button. This version has a combined PSU/pre amplifier board.
I have replaced most (large) electrolytic capacitors in the PSU, as these were “bulged”, completely dried out and no capacitance at all.
After the repair and switch on, strangely a small capacitor blew up on the Hypex NC102 power amplifier board. After that all elco’s on the NC102 were also replaced.

At present the Powernode is mostly working again: staring up normally, can be seen from the BluSound app, music can be streamed and headphone output working.
Only the NC102 power is not working. It appeared that +/- 42V power is missing.

It is very hard to debug this failure, as traces on the PSU board cannot be traced on the PSU board. Probably an active element in the switched power supply has failed.

Can someone help me with a schematic diagram of the Bluesound Powernode N180?

(if copyright issues prohibit this, please send me a DM).

Many thanks in advance,
Martin Deisting
The Netherlands (proud Home of Hypex!)

Troels Gravesen Illumina 66 Build Log

Thought I would share this here, posted elsewhere before, nearing completion now.

I had the tweeters laying around, so I figured I would go for these.
I am using a simplified geometry to make build easier, but keeping angled parts to eliminate standing waves. I modeled it in Solidworks so I could calculate internal volume with all bracing in place (have not done bracing yet). Here is the basic geometry:
index.php


Next step, build a little scale model section to make sure everything is going together well, I dont have that much woodworking experience.
6lkFWi2.jpg


So far so good, time to get the wood, got nice sheet of MDF
Y7K0YLQ.jpg



A few other notes on the build

I am using double thick front panel for rigidity.

Also, these speakers are very very similar to YG acoustics Carmel 2.
The tweeters all almost the same - YG uses scanspeak tweeters custom made for them, with I believe a slight difference.
The woofers are also very similar: Same size, same basket and motor structure. Only difference I see is YG makes machined aluminum cones that they send to scanspeak to be used, while the regular scanspeak drivers use pressed aluminum cones.
Other differences, the waveguide built into the YG speakers, crossover differences, YG have an internal resonation chamber instead of a port to outside, and of course, the YG cabinets are machined aluminum.


Front baffle going well, tweeter flush mount looking all good. I was a bit concerned, never built speakers before, or did a flush mount, but it seems to all be going well.
4D4OUg3.jpg


And woofer hole cut as well, ordering woofers now to test fitment
index.php


Woofers arrived
index.php


Sexy magnet structure
index.php


Test mounted, starting to look like a speaker
index.php

Regulators right beside OPamps pins

G'day Guys,

I am currently designing a PCB for a fairly bog standard phono stage based on the NE5532. Nothing fancy or important here.

The typical way I would handle the power supply would be something like some 7815/7915 regulators on an off board power supply pcb.

Is there a good reason not to put the 7815/7915 regulators right beside the OPamps power supply pins?

Is there a technical reason not to do this?
I can think of cost reasons but it seems to me like putting the regulator right beside the OPamp with the regulator output cap functioning as the OPamp decoupling cap to be superior.

Comments and analysis needed on the new crossover modification

I've modified my beloved commercial speakers; Braun LS200. In fact, these speakers sound decent, at least to me, and they received many positive reviews. But that was about 40 years ago--in the 80s era. If compared to nowadays speakers, they aren't perfect speakers though. They have a lot of cabinet talk. I solved this problem by try reducing mid-bass output from the dual 10" woofers. It was achieved by reducing Q of the woofers' low-pass to allow amplifier to provide more control to the woofers. Then, a slight EQ on the upper high region was added, by means of increasing Q of the low-pass of the 2" dome midrange to gain a couple of SPL there. Finally, the mid-high region was too strong as a result of midrange's mod. Hence, I decrease some duty of tweeters by raising their cut-off frequency a bit. All of these were done with extensively use of simulations on VituixCAD.

For technical detail:
Woofer - the 100uF capacitor was replaced with a lower capacitance of 68uF to lowering mid-bass output and gained lower Q at the same time.
Midrange - the 33uF capacitor on the high-pass section was replaced with lower capacitance of 22uF to flatten frequency response curve that was risen due to the woofers' midrange reproduction. And The 14.7uF capacitor on the low-pass section was replaced with 22uF too to produce more mid-high region for personal preference.
Tweeter - there was an overlap at mid-high region as a result of midrange's mod, the solution was to reduce some duty of tweeter's operating range. Consequently, the 6.8uF capacitor was replaced with 3.9uF.

I need some opinion, analyzing or even criticizing on my modification such as pros and cons, should do and should not do suggestions, although I am already satisfied with it.

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Distributor Body DIY

Hello Everyone,

I'm looking for power distribution body/box, where I can put 5 – 6 Schuko outlets of Furutech FT-SWS or FT-SDS. I need either finished products, or place where can make specific size. The body I need is very high quality: thick, solid, heavy, and stable. To insure stability and minimize vibrations.

Anyone know, and what best material used (Aluminum, Extrude Aluminum, Steel … )?


Thanks so much.

For Sale Ian canada reclocker

Hello everyone,

Im looking to sell some Ian canada stuff
1. Fifopi Q7- $140- sold
2. Fifopi Q3-$80
3. Reclockpi - $30
4. Scpure clock 45.158 mhz - $130- sold
5. Hdmipi Pro - $70
7. 2 ucconditioner 5v with ultracap - sold
8. 2 ucconditioner 3.3v with ultracap- sold
9. uconditioner 5v- 60 each
10. Unconditioner 5v- 60 each
11. unconditioner 3.3v - 60 each
12. Unconditioner 3.3v - sold
13. Transportpi - sold

Pictures to follow

Buyer pays shipping and paypal fees.

Thanks

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New full diff amp OPA1637

TI continues to surprise us with top notch products. After the OPA1656 I 'discovered' the OPA1637. A fully differential amplifier with excellent audio specs.
Ordered the eval module to get a head start*. I can see several places where this would fit very well, like fully balanced post-DAC filtering and/or I/V conversion, fully balanced preamps, fully balanced active filters/xovers. And, my own target, an improved fully balanced AutoRanger.

Anybody here with similar ideas?

Jan

*If the international shipping system holds up, hopefully.
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QCC3034 Programing with TRBI200 - BlueSuite 3.3.18.2017

Hello All,

I'm trying to change the Bluetooth pairing name on my QCC3034 Bluetooth chip. This chip is integrated into the Amplifier board im using on my project (Wondom JAB5). I was told by Wondom that I can accomplish this by using the Qualcomm TRBI200 via QCC_Tool. I purchased the TRBI200, downloaded the latest version of BlueSuite which comes with the latest drivers for the TRBI and can get my computer to recognize it. The problem im having is that BlueSuite and QCC_Tool does not recognize it or detect it. Am I missing something here? Do I need any additional steps to activate the TRBI so that it can be detected by the Qualcomm software? I created the key file and unlocked it as well, but does not help. fyi, I'm using the MOSI, MISO, CLK, +3.3v, GND pins for this. I'm also using Windows 10.

Any suggestions will help, thanks in advance!

Hello, Kolchak from New Jersey, USA

Hello. I'm from New Jersey, USA. Have been an electronics experimenter since a child in the 1970's, and building/repairing audio equipment since then too. My nickname Kolchak comes from the 1974 TV series Kolchak The Night Stalker, hard to believe it premiered 50 years ago! Time flies! I remember when our local electronics store, had rows of vacuum tubes behind the counter!

Kind Regards - Kolchak

For Sale Deltec DPA Enlightenment DX32 DAC

Great vintage DAC based on DPA's discrete 1-bit current-pulse convertor.

Faceplate in good condition for its age, casework a bit scratched sadly. Most importantly all working and sounds very good.

Coaxial RCA and Toslink inout. 1 x RCA phono output.

Pics to follow soon when better light available.

Will sell for £225 inc. UK postage given cosmetic condition.

Collection from Edinburgh possible.

Thanks

Eastone

Markaudio CHR-120 Test and Review

I would like to share my blog post where I do a full test with measurements on the CHR120 along with subjective listening impressions. The cabinet is 28 liter tuned to 40Hz.

https://josephcrowe.com/blogs/news/markaudio-chr120

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Pass X150.8 combatibility

Folks,

I've started my Pass Labs journey with the purchase of a X150.8 power amp earlier this month. The reason for this post is that I've had a BAT system comprised of a VK-55SE tube amp and a VK-80 tube preamp. It was a great system-open rich holographic. Fast forwarding I still have the tube preamp which is driving the X150.8 (driving Zu Def. 3 speakers). However, presentation seems veiled, loss of texture, detail of instruments and voice, and note decay. What it does bring over the old system is rock solid expanded space (wide and deep) and much better localization than previous set-up. Per a friend's advice who owns a X350.8 mated with a XP-22, I was advised to let it break-in a week or two. At this point not much of an improvement.

So the ultimate question is it a break-in issue, component mismatch, or some other issue that may be causing the issue? My earlier research based on impedances pushed me towards "no issues" since the X150.8 has 100k input impedance, while the preamp is at 300 ohms.

My ultimate objective is to have an entire Pass system to replace my original tube system (having equal or better SQ). However, I was hoping that would be later than sooner due to the investment just made. Anyway, just doing a sanity check.

Many thanks.

Neil

Restoring Panasonic RS-280S

I have a Panasonic RS-280S receiver that I'm working on restoring. Link with pics of this receiver: https://www.hifiengine.com/manual_library/panasonic/rs-820s.shtml . Everything works on it except the light bulbs and the meters showing the output to each speaker. Where can I get all new bulbs and meters for this receiver? How do I replace them, anybody with previous experience?

You are welcome to come to us for customized cartridges!

ae8972c8c51c8fe5106d35c485e2631.jpg
We are currently developing hi-fi MC cartridges.You are welcome to come to us for customized cartridges!

We can accept MC vinyl cartridge customization, such as different types of needle bar customization, different voltage output customization, etc., individual appearance customization, etc.

Depending on the configuration, the price is also different. Interested friends can take a look at the samples in our store first. Of course, the price for bulk orders will be lower than the retail price.

https://www.ebay.com/itm/204703055422
https://www.ebay.com/itm/204571396117

Please help compiling a list of DACs and DAC chips with and without intersample over issues

Hi everyone,

Many music recordings are normalized such that the largest samples are full-scale, but after interpolation, the signal then usually has to exceed full scale. This often makes digital interpolation filters go into hard clipping, as they are rarely designed to handle this. The recording itself is not clipped, but it makes an interpolation filter without headroom clip. Benchmark Media has dubbed this intersample overs, and found that some recordings have hundreds of intersample overs, see https://benchmarkmedia.com/blogs/application_notes/intersample-overs-in-cd-recordings

When you use a digital volume control, it depends on the exact implementation whether it solves the issue. If the volume control is done before any digital filter and if it is set a few decibels or more below maximum volume, then there is no problem. If the signal first passes through an interpolation filter with no headroom and then through the volume control, reducing volume won't help.

At the end of a now-closed thread, @jean-paul asked me to compile a list of DACs with and without intersample overshoot issues. Unfortunately it will be a very short list, because I have no information about most of them.

Some four years ago, I made a test signal that makes it very easy to determine whether a DAC has or hasn't headroom for intersample overs. It consists of two high-pitched sine waves that produce very audible intermodulation products in a DAC that clips on intersample overs. The test signal and an explanation (in English and Dutch) can be found in the attached zip file. There are two other audio files, depending on whether there is an issue, the test file will either sound like one or the other.

Could everyone who wants to participate play the test signal over their DAC with the digital volume control at maximum and a bit lower than maximum, compare the sound to the other two files and report the result and the DAC or DAC chip model? I will then add the results to the list. To prevent blowing up your ears and your tweeters, the volume should not be too high, so don't do the test if there is no way to control the volume on the analogue side.

Thanks in advance,
Marcel

P.S.: when you play it from a computer, you have to make sure somehow that the computer doesn't change the volume and doesn't do any sample rate conversion, otherwise you might be testing your operating system instead of your DAC.

Lists:
DAC or DAC chip model: clips on intersample overs at full digital volume; clips on intersample overs at reduced digital volume setting (if applicable)

Valve DAC of Linear Audio vol. 13: no; no (the only digital gain settings are 0, -6 and -12 dB)
Typical NOS DAC: no; not applicable
AKM AK449x DACs with the exception of AK4495: probably; no
Gustard X16 (ES9068AS): yes; no (-2 dB)
ES9039Q2M (bohrok2610's DAC): yes; no (-1.5 dB)

Sample rate converter model: clips on intersample overs at full digital volume; clips on intersample overs at reduced digital volume setting (if applicable)
Foobar2000 with RetroArch (resampling to 176.4 kHz): yes; no (-2 dB)
Texas Instruments SRC4392: yes; probably

It should be noted that sample rate converters that have essentially the same fixed-point number ranges at input and output cannot have 0 dB gain without intersample over problems, at least not when they are interpolating.

Attachments

Phil Lesh, RIP

I learned about it via mention from another player at the open mic last Friday. He then played a song in tribute. I changed up one of my three to "jack straw", which I played with all the finesse of a bulldozer clearing a patch of land. Someone later told me he hadnt heard that in 20 years, so I must've rendered it in at least recognizable form, for Phil.

Saw a video discussion on YT with Phil. He's an audio guy; they talked of the Wall of Sound, how the mics worked and he even knew what the capsules used were for and why that didnt serve so well for vocals. He said his bass had an individual output for each string, but he never used it "too confusing",

I've also read his book "Searching for the Sound".

RIP Phil

Hey everyone

Hello,

I'm excited about having joined diyaudio. I'm very much looking forward to improving my diy skills and to contribute to the community where I can.
I did build some speakers from soundblab and now I started to create and calculate my very own projects.
The first was a very cheap TL with the fabulous Markaudio CHR70. I'm about to finish the filters.

Cheers
Roesel

Making Windows 11 more usable, less annoying, and an easier transition

I am going to try and document the configurations and setting I am making on a fresh win 11 install to reach the goals of the title. If possible.

1. first thing I am left shifting the task bar and un combining taskbar icons and labels. This setting is under taskbar behavior.
2. Uninstalling bloat ware.
so I just searched for programs and features and was forwarded to apps/installed apps and was able to uninstall a lot of things that I do not need. I have a suspition that this is the short list of installed apps and that I will have to use powershell to get an actual appx list but that is in the future if needed.

3. Should have been first but using advanced system settings, select best performance and then re place the check mark for show thumbnails. the advanced system settings are in settings / system / about.
4. Oh my! what can be done about the start menu? I'm searching now.
wasn't so bad used personalization / start to get more pins and turn off some recommendations.

5. Just found other software hidden in system components game bar / phone link ect. Will try and uninstall some things without power shell for now.

6. no update today except to ask how some of the responders think that they can talk an office manager into paying me hundreds of units of money to put a different start menu on the office workstations. One person in this or the computer thread suggested that the employees should get different jobs because of the operating system.
Again my point for this is to get the best out of it not replace it.

Sorry for the rant, so things bled over from the computer thread

9-10-24 6PM gmt-5
7. open up task manager and turn off auto startup for one drive and edge (I suspect that this will be turned back on by updates.)

8. go to settings / accounts / your profile and switch to "sign in with local account"

9. update powershell help
update-help
run this in powershell as admin
Get-AppxPackage > c:\list
open c:\list with notepad
find the packages that you don't want but remember if you don't know what it is then ignore it for now

As a goof I ran" Get-AppxPackage -Name xbox | Remove-AppxPackage" to remove packages with xbox in the name and I removed "your.Phone" I will let you the repercussions.

9.001.
I have installed 10 on another machine and let it upgrade to 11 so that I have a base line. This base line machine will not be modified beyond personalization settings.

I am setting this base line PC because I am starting to think that it is fine for the common user with little more than letting onedrive run but don't sync your folders other than the default one drive folder, installing a preferred web browser and turning of suggestions.

Intro from Exited New Audiophile

How's that for an intro? I was introduced to this sport of "buy and hope 'they' don't find out" by a well experienced friend who didn't know when to quit and now owns an entire good sized pole barn full of any type of audio equipment we could dream up. I currently own two stereo sets myself, including a pair of AR bookshelf-sized speakers. I have components and plans to build a pair of La Scalla style of speakers. Also have a Panasonic RS-280S receiver that I'm working on restoring. Link with pics of this receiver: https://www.hifiengine.com/manual_library/panasonic/rs-820s.shtml I'm not sure if I should start a new post on these projects somewhere else on the site or can they be discussed on this thread? Things I want to know on these projects: Where can I get all new bulbs and meters for this receiver since they of course all burned out? How much is this thing actually worth if I sold it, like will it be worth my time restoring it? Where could I get build plans for my speakers?

QSC RMX2450 Plays for a while Audio after turning off

Hi guys, I'm new hear.

Im in no way an electronics expert, but i do dabble swapping out faulty capacitors in power supplies, and faulty pots in amps etc.

So i have a few QSC RMS 2450 amplifiers. Only one of them has this strange issue.

When i turn it off, after a few seconds, the clip lights light up and distorted audio can be heard. After maybe 6 seconds of this, the clip lights go out and none distorted/ clear audio can be heard. I can even turn the volume pots up and down and it controls this audio as if the amp is still on, although it's not putting out the same sort of volume as when the amp is on.

This will carry on for maybe 30 seconds or so, untill the amp completely goes off and silent.

I'm guessing it's something to do with discharging of capacitors, but can anyone explain why this is happening, why this is the only one of maybe 8 of these amps I've had over the years and how i fix / solve it? Thanks

Pioneer PDR-509

Working on a clean looking Pioneer PDR-509 CD recorder. When I first powered up the main display cycled through "CD?" CDRW?" CDR?" (or something close to that) and then eventually settled on "Check Disc". This occurred no matter what type of disc I inserted including pre-recorded music CDs.
Cleaned lens with IPA and added some grease to the transport rails. No improvement.
Obtained service manual to locate the playback laser adjustment. I didn't follow the procedure in the manual closely because I don’t have a laser power meter. I found that adjusting the VR101 pot prevented the constant spinning and "check disc" errors. Now when inserting any type of disc it spins down quickly and reads "no disc". At this point VR101 has been turned almost completely ccw which seems wrong anyway. Do I need to follow the adjustment procedure in the manual and have the unit in test mode (which I initially did) for the adjustment to work? Is there a way to do this without a laser power meter?

When activating the error code display (holding stop) I get a reading of "5100 00". Seems to indicate no error, but is the maxed out hour count a clue to something? Should I reset the hours?

My understanding is that the 509 doesn’t have issues from a super cap like some other models. Is there something similar I can try?

I would consider dropping a complete replacement drive in the unit if it were feasible and inexpensive.

I'm mostly interested in using it as a playback unit. I might end up just scrapping the whole thing. Any opinions on whether it's worth anything as-is for parts on Ebay?

Thanks.

wide frequency dip at 100Hz when measuring both speakers

When I measure my Markaudio Alpair 10.2 TQWT speakers separately at the listening position I see no dip around 100Hz, but when I measure both speakers at the same time (orange) a wide dip occurs at 100Hz. It seems as if both waves at the listening position get out of phase at 100Hz. I have the same effect with Harbeth P3 speakers. Does anyone understand this effect and how it can be corrected?
Maraudio Alpair 10.2 TQWT L-paars R-blauw RL oranje.jpeg

QUAD 909 Clone

Original source is here, just to make it clear that these are not my designs. Since i don't speak bulgarian, i can't ask anything about the design so its far easier to post it here. Quite fancy building this design as i've always fancied a quad. (did look at the 405 designs too) I am not certain whether I can substitute the 2SA1837 toshiba parts out for something like sanken 2SA1859A. It also suggests using ZTX552 for T5 which i can't find and ZTX752 for T6 which i've substituted for ZTX753. Are the MJL21194 main outputs the best or is there a better part. (the parts list i have differs from the parts on the schematic)

Last of all, the power supply design that i was intending to use was a 2x 50V 625VA toroid with 2 rectifiers filtered by 4 22,000uF caps. I noticed that the original 909 psu has some additional components and the +/- rails are offset. (+57.8V and -53.4V)

Schematic. I also have the Eagle design files with both schematic & pcb.
Quad909Sch.jpg


PCB
PCB.png

When enthusiasm overtakes sanity and science

Hi All 🙂

Long term lurker from India. Have had some decent speakers from the likes of PMC in the past. However, looking for a change as we all do, I ended up getting a pair of 3 way DIY speakers built with the SB Acoustics Satori. These have startled me, in a most pleasant way. And now I cant stop looking for the next big idea.

I must admit that, at this point in time, Iam driven by enthusiasm rather than dry science. And I've probably dived at the deep end of the pool in my first attempt to swim, by purchasing the drivers for my first OB build.

Looking forward to reading and learning and sounding out my duff ideas against the combined wisdom of the forum. Thanks for having me here 🙂

Thanks and best regards
newlash09

Greetings from The Agitated Scientist!

Hello!

I'm a life long audio enthusiast and obsessive tinkerer. I started by taking apart my uncle's old HAM radios just to see what was inside. If only I had a few of those gems around now! I do however have a pretty large collection of pro and semi-pro recording gear in my studio, as well as quite a few home hifi systems and odds and ends. I'm the guy everyone brings their broken or unwanted stuff to. I try to pick through it all and these days about 60 or 70% of the time I'm actually able to render it useful (at least to me)! No matter what, I always learn something new when I tear down a piece of equipment. But alas, surplus audio gear is a bit like a homeless pet: try as I might, regretfully I can't save them all.

Looking forward to getting and possibly contributing some great advice to the experts on this forum.

Thanks,
Ryan Freeman
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230V/20W Led bulb glows clearly visible in the dark with only 4uA of current

I changed a 75W bulb into a 20W Led bulb.
At nigth i notized the bulb glows faintly, but clearly visible through the milkglass cover (its a lamp outside my front door) even it is not switched on.
I suspected leakage from a faulty switch or cable.
But leakage resisistance was unmeasurable high.
Next i measured the current, 4 uA !
Gotta be capacitive coupling, i have no other explanation, less than 100pF seem to be enough for that bulb, truely amazing
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Help me to find a way to learn designing Speaker Drivers

Hi, i am really interested in learning Audio transducer design but do not know where to start. I have knowledge in building speaker enclosures now i want to learn designing and simulating the driver it self. If any one of you can help me with the subject please suggest me a way that helps learn audio transducer designing.
Thank you
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B&W 601 (original) Tweeter questions.

Hi again 🙂

Ok, I know that there are numerous threads on 601 tweeters, but I'm now looking at 'near-equivalent' replacements, and wondering if anyone has tried any?

My pair of B&W 601 (the original - I guess S1?) are suffering from the typical defunct tweeters - both of them. I knew this when I bought them - I got them cheap for that reason. I fancied the challenge of fitting new dome-coils, but that isn't turning out too well even tho' I figured I positioned them spot-on... I also topped up the ferrofluid - perhaps too much?! Interestingly, the tiny feed wires on mine look as tho' they were vaporised - someone must have driven them hard.

Anyhoo, whilst I keep experimenting with a tweeter repair, I'm also looking at other options such as a near-equivalent replacement. I am not concerned about the physical aspect of the installation as I'm reasonably confident I can tackle any mods required, but just that it is a close audio spec match to the original. There must be hundreds of folk looking for this, as these superb speakers are failing almost always due to their obviously-delicate tweeters.

I don't think there's any mileage in buying 'genuine' second-hand replacements, as their lives will be of an unknown span. Brand new (say S2 or S3) B&W tweets are silly money, so again are out of the equation as these are old speakers that barely justify this. So, that leaves either a successful 'repair', or an equivalent fit.

Sooooo, any ideas folks? Someone must have tried this?! Or am I going to have to be the first?! I've read they 'cross-over' at around 4kHz and are 4 ohm resistance, so surely any decent quality tweeter of that near-spec will work well?

So, any ideas on near-equivalent tweeters? 🙂

Thanks.

Help needed from you experts!

Hello guys, my name is Graham 2439. I've just inherited a Marantz CD273 Special Edition CD player - no extras, manual etc.
The item seems to be working - all lights and buttons live. I have hooked it up to a pair of old Wharfdale speakers and I can faintly hear that it's working, but there is no volume and it appears no control on the player. QUESTION: do I need an amplifier and if so could someone tell me what I should be looking for?
Many thanks for any help

Harman Kardon PA-2400 Distortion question

I just finished working on a PA-2400. Recapped it and replaced the carbon film resistors in the signal path with metal film. The amp was in good working condition prior to the work. The distortion I measure before and after are very similar. The spec quoted by H/K is:
1729981254804.png


When I measure 1kHz @ 1 Watt I get higher distortion:
Distortion after recap and bias adjust.jpg


When I measure at ~72Watts distortion numbers are better:
Distortion Oct 26 @ 72 Watts.jpg


Do you think this is normal for a PA-2400? Does anyone happen to have one?

In general, what would cause the harmonics? The amp sounds great to me, and I don't want to go chasing a problem that isn't a problem.

Attachments

  • Distortion after recap and bias adjust.jpg
    Distortion after recap and bias adjust.jpg
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Wuzhi Audio brand problems

Wuzhi Audio markasından bir Çin amfisi aldım ve hatta 150 W aldım. Benim sorunum Bluetooth veya AUX ile bağlandığımda müzik sesi cihazların gövdesinden geliyor. Hoparlör bağlasam da bağlamasam da.

:cop: Translated I bought a Chinese amplifier from Wuzhi Audio brand and even got 150W. My problem is that when I connect via Bluetooth or AUX, the music sound comes from the body of the devices. Whether I connect speakers or not

My first tube preamp

Hi. I am new here in the forum. I am planning to build my first tube preamplifier pair with my solid-state power amplifier. I am not a circuit designer, and I am not so good at technical stuff, but I have done a few DIY amplifier assemblies by myself with the help of schemes. So I am open to suggestions of a well-made pre amplifier board/kit to start my work. Because I can't work an amp from scratch, a preamp kit will be a nice option.

When I was going through many posts here in the forum, I was a bit confused by the lot of preamp boards.I want to learn and upgrade little by little to understand the sound. That's why I am planning a DIY path. I don't know if I can do this with my zero knowledge, but I am very much willing to build one.

I hope you all can guide me. Thank you so much 🙏.
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