@jdg123
bit extensions... well, well.
a wonderful example of imaginative invention.
good stuff
bit extensions... well, well.
a wonderful example of imaginative invention.
good stuff
Hey guys... A little help here. I have this amp running, but noticed something on one channel. I did some testing and one channel has a 3khz signal about 12db above the other when the fundamental is 1k into 8ohms. The other is running about 92db down the other about 80.
A little help on where to start looking?
JT
A little help on where to start looking?
JT
Third harmonic is way high on one channel compared to the other. In this case the 1k fundamental and the 3k harmonic it 15db higher on one channel than the other. I didn't try other freqs yet, but it looks like the one channel has something going on.
This isn't a testing issue, the amp is doing something naughty. 🙂
I would get a pic, but I was testing all day and hooked it back up to listen to some music. If you still would like a screen shot of each channel, I will get them online for you tomorrow.
J
This isn't a testing issue, the amp is doing something naughty. 🙂
I would get a pic, but I was testing all day and hooked it back up to listen to some music. If you still would like a screen shot of each channel, I will get them online for you tomorrow.
J
now I got it
I (p)resume both channels are behaving, regarding most important currents and output DC offset
can you compare currents of all verticals, between channels, and write that here?
that must show where possible culprit is
that would be (looking at schm in post #1):
voltages across R1,R2,R15,R7,R11
of course, regular check of all resistor values is logical, per se
I (p)resume both channels are behaving, regarding most important currents and output DC offset
can you compare currents of all verticals, between channels, and write that here?
that must show where possible culprit is
that would be (looking at schm in post #1):
voltages across R1,R2,R15,R7,R11
of course, regular check of all resistor values is logical, per se
I stripped everything out of the path. I stream in the lab from computer and they chain is a little complicated because I have several pre and amps that I rotate in. Therefore many RCA cables and a switch.
I pulled everything from the chain and swapped one RCA at a time. I found one RCA was the issue.
KISS 🙂
I pulled everything from the chain and swapped one RCA at a time. I found one RCA was the issue.
KISS 🙂
Indeed... I've been hearing something for some time and it was only through the Quant that I could see it. Also, I am going through interconnects and cables to check and see how they perform.
Very cool to be able to see it right there on the screen.
Very cool to be able to see it right there on the screen.
Waynes amp tests very good... I streamed a 1k tone from my computer outfit USB to the HoloSpring KTE Dac and from that RCA to Wayne's amp, out of Waynes and into the Quant.
This is basically a real world test as Waynes signal will now go into the Badger or SIT-3. The first looks pretty, but is attenuated. The second in not and is more sensitive as should in the pic.
This is basically a real world test as Waynes signal will now go into the Badger or SIT-3. The first looks pretty, but is attenuated. The second in not and is more sensitive as should in the pic.
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Looks really good, Thompson. Given the fine work you did with the circuit a while back, it is nice to see the fault lay elsewhere 🙂
I picked up the BA2018 PCB and Parts Kit the last time I ordered from the DIY Store. I've searched through this thread for all references to building it with balanced outs but most of them simply say that you need two sets of boards etc. to make it with balanced outs but they don't say how to wire them. The post by Astromo is the exception. He included a PDF with wiring Wayne's BA 2018 linestage. Is that the correct way to wire the boards if I want to build it balanced in and balanced out?
Also, I have an extra PSU that I built for the First Watt amps. It outputs 24V DC which is on the high end and obviously a lot of current. Will I fry the BA2018 if I use it as the power supply?
If I do need a new power supply does anybody have a recommendation for a prebuilt PSU that I could buy or do I have to build it from one of the board designs like VRDN?
Thanks.
Paul
Also, I have an extra PSU that I built for the First Watt amps. It outputs 24V DC which is on the high end and obviously a lot of current. Will I fry the BA2018 if I use it as the power supply?
If I do need a new power supply does anybody have a recommendation for a prebuilt PSU that I could buy or do I have to build it from one of the board designs like VRDN?
Thanks.
Paul
to PaulInWA #2591
Hello PaulInWA,
my Wanes Line Stage is running on +-24 V DC. I never had a problem.
If I would use it for balanced operation: one board for one channel (makes it dual mono - complete channel separation).
Then I would feed the + audio-signal into the right channel and the -audio signal into the left channel of one pcb. One possibility 😕
Cheers
Dirk 😀
Hello PaulInWA,
my Wanes Line Stage is running on +-24 V DC. I never had a problem.
If I would use it for balanced operation: one board for one channel (makes it dual mono - complete channel separation).
Then I would feed the + audio-signal into the right channel and the -audio signal into the left channel of one pcb. One possibility 😕
Cheers
Dirk 😀
What is the opinion among experts about using an unbalanced to balanced converter with, for instance, a THAT 1646 or something like that? Makes the options for a volume control a lot easier.
Good to know that it can run on +-24VDC but does the PSU board from the DIY store that is used for most First Watt amps put out too many amps to be used with Waynes Line Stage?
Paul,
The diyaudio PSU board that everybody uses for their First Watt clones are meant to supply boards that use large amounts of current, as in amperes of current, if configured with the large capacitors, etc... That being said, you won't do any harm powering your Waynes BA2018 linestage with them, it's just absolutely overkill to do so. Think of the diyaudio PSU board as a large capacity reservoir. You just draw your current from that reservoir, it doesn't overwhelm the circuit it is supplying. That's a common misconception/myth.
That being said, form does follow function (it does follow consumption as well judging by the obesity epidemic I see every day in this country, but that's a little off topic).
So let's discuss other power supply designs that might fit the needs of a Wayne BA2018 linestage/headphone amp.
If you have the option, I would suggest the VRDN supply as it is more apt for smaller current hogging designs. You can also use Jan Didden's Silent Switcher V3 which is fully built but you need to supply it with a 5V-10V dc source. The Silent Switcher has an advantage in that it is eminently portable since it can work off of an iphone or similar charger and avoids the use of heavier toroids, caps, etc...It is scaleable up to +/-15V DC @ 150mA or a little more. The VRDN can supply considerably more current (1.5A) and is scalable from +/- 11V DC to +/- 20VDC or thereabouts. Also, depending on how you look at it, the Silent Switcher is a more advanced level DIY project. Judging by your post, you are just getting your feet wet, so give the VRDN supply a try if possible. There are loads of friendly folks there ready to help. The VRDN was designed for the beginner and MJ has written a very nice writeup in that regard (see link above).
There are several other examples of power supplies that can be used with Wayne's linestage which have very small power requirements. I just haven't finished my morning cup of coffee yet 😉!
Best,
Anand.
The diyaudio PSU board that everybody uses for their First Watt clones are meant to supply boards that use large amounts of current, as in amperes of current, if configured with the large capacitors, etc... That being said, you won't do any harm powering your Waynes BA2018 linestage with them, it's just absolutely overkill to do so. Think of the diyaudio PSU board as a large capacity reservoir. You just draw your current from that reservoir, it doesn't overwhelm the circuit it is supplying. That's a common misconception/myth.
That being said, form does follow function (it does follow consumption as well judging by the obesity epidemic I see every day in this country, but that's a little off topic).
So let's discuss other power supply designs that might fit the needs of a Wayne BA2018 linestage/headphone amp.
If you have the option, I would suggest the VRDN supply as it is more apt for smaller current hogging designs. You can also use Jan Didden's Silent Switcher V3 which is fully built but you need to supply it with a 5V-10V dc source. The Silent Switcher has an advantage in that it is eminently portable since it can work off of an iphone or similar charger and avoids the use of heavier toroids, caps, etc...It is scaleable up to +/-15V DC @ 150mA or a little more. The VRDN can supply considerably more current (1.5A) and is scalable from +/- 11V DC to +/- 20VDC or thereabouts. Also, depending on how you look at it, the Silent Switcher is a more advanced level DIY project. Judging by your post, you are just getting your feet wet, so give the VRDN supply a try if possible. There are loads of friendly folks there ready to help. The VRDN was designed for the beginner and MJ has written a very nice writeup in that regard (see link above).
There are several other examples of power supplies that can be used with Wayne's linestage which have very small power requirements. I just haven't finished my morning cup of coffee yet 😉!
Best,
Anand.
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Other options, all mentioned somewhere in the thread, are PSUs from
Glassware Audio
AMB
Salas Ultrabib
I run mine with a VRDN, really very nice combo...
In the links above, you would have to find a PSU that fits...
Glassware Audio
AMB
Salas Ultrabib
I run mine with a VRDN, really very nice combo...
In the links above, you would have to find a PSU that fits...
AMB σ22 is one of my all time favorites, but it is a large PCB design, so I reserve it for my best projects. It is a slightly more advanced build.
You'll want to aim for a power supply that is at least +/- 12V so you can get adequate voltage swing from Wayne's design depending on your needs of course. Headphone enthusiasts should be happier with +/- 15V or more and some modifications that 6L6 had mentioned to the output stage (alternative BJT's).
I'm currently working on a MOFO and I have Wayne's BA2018 with +/- 18V using the VRDN supply to be fired up hopefully by this weekend.
@cubicincher,
Thanks!
Best,
Anand.
You'll want to aim for a power supply that is at least +/- 12V so you can get adequate voltage swing from Wayne's design depending on your needs of course. Headphone enthusiasts should be happier with +/- 15V or more and some modifications that 6L6 had mentioned to the output stage (alternative BJT's).
I'm currently working on a MOFO and I have Wayne's BA2018 with +/- 18V using the VRDN supply to be fired up hopefully by this weekend.
@cubicincher,
Thanks!
Best,
Anand.
Thanks to poseidonsvoice and myleftear. I had missed the Silent Switcher and the fact that it is available in the DIY Store. That is an interesting solution. I'm intrigued by the idea of running it off a power bank though I have no idea if that makes any real world difference in the quality of the output. I also found a guy with a couple of extra VRDN boards that he is willing to sell me so I will have that option also.
But since I have an extra PSU that I built for a First Watt amp I think I will start with that if you guys are confident it won't fry the BA2018. I've built several of the First Watt amps but my actual knowledge of circuit design dates back to when I was a teenager almost 50 years ago and I didn't understand much then and remember even less now LOL.
But since I have an extra PSU that I built for a First Watt amp I think I will start with that if you guys are confident it won't fry the BA2018. I've built several of the First Watt amps but my actual knowledge of circuit design dates back to when I was a teenager almost 50 years ago and I didn't understand much then and remember even less now LOL.