For the other members. I don't believe this information accurate. Please refer to the table in the first post as a guide for output power and rail voltage requirements. Once boards are ordered there's a specially designed SPL including dynamic range vs Rail voltage spreadsheet that @fireanimal and I put together, and, is available in the Dropbox folder that contains all the files for this project.
DIY Class A/B Amp The "Wolverine" build thread
- Thread starter stuartmp
- Start date
stocktrader200 meant that lower rail voltages have more margin against thermal runaway.
BTW, I measure 100mW peaks with 83dB/W speakers at my normal listening level.
Ed
I was pointing out the the amp does have greater margins of thermal safety at lower voltages while also stating I rarely ever take my amp over a few watts and most listening is well below a watt. Higher rails are not beneficial in a practical sense.
More than 40-50V is where cost becomes significant.
Ed
Ed
For whisper mode I would opt for a set 90dB/Watt speakers and a class A amp running from low rails. What's your motivation for diving in the Wolverine design?
The Wolverine and my amplifier are both high-power, class AB, bipolar transistor amplifiers. I have been designing amplifiers as a hobby for half a century.
That being said, I don't like loud sounds. My criteria is that after listening to music, if normal sounds seem quiet, then the music was too loud.
Ed
That being said, I don't like loud sounds. My criteria is that after listening to music, if normal sounds seem quiet, then the music was too loud.
Ed
Well I started building amps when I was 12 yo, and I am 74 yo now. And while I do give them a personal touch now and then, I would not claim I am designing them, it would be euphemistic. Everything that can be designed has been designed, and when something new turns up it's usually the semi manufactures or professional designers that have thought it up. Actually this amp your at now, the Wolverine, is very close to some Harman Kardon designs. ostripper was always open about getting his inspiration from there. And if that's not enough it's also a perfect example of a blameless design as published by Douglas Self in his book.
At the moment I am working on a design for a housekeeping circuit around an ATmega processor, you find it a few pages back in this thread. I be interested to learn about your designs, and am also still looking forward to the answer on my question from #3745.
Ed
At the moment I am working on a design for a housekeeping circuit around an ATmega processor, you find it a few pages back in this thread. I be interested to learn about your designs, and am also still looking forward to the answer on my question from #3745.
Ed
I read all threads about good amplifiers. The Wolverine is an example of the current state-of-the-art.
I agree that there are not many different ways to design good amplifiers. My design is unpublished, but it was based on the Leach amp. I made a number of improvements. The current version is from the year 2000. Ostripper's "Spooky" amp is the most similar design on this board.
I don't feel a need for class A because class AB can deliver performance that is perfect for all practical purposes. The amplifier can play at 35dB below clipping without showing any downsides.
Ed
I agree that there are not many different ways to design good amplifiers. My design is unpublished, but it was based on the Leach amp. I made a number of improvements. The current version is from the year 2000. Ostripper's "Spooky" amp is the most similar design on this board.
I don't feel a need for class A because class AB can deliver performance that is perfect for all practical purposes. The amplifier can play at 35dB below clipping without showing any downsides.
Ed
What happened to C11??
Guys- I am trying to stuff an old 1st buy EPS board and there is a space for C11. This does not appear in the newer boards, nor does it appear in the BOM or schematic. Does anyone recall what this cap did? Can I just leave the slot empty?
Thanks!
Jon
Guys- I am trying to stuff an old 1st buy EPS board and there is a space for C11. This does not appear in the newer boards, nor does it appear in the BOM or schematic. Does anyone recall what this cap did? Can I just leave the slot empty?
Thanks!
Jon
Leave it empty. Was removed.
See here
https://www.diyaudio.com/community/...he-wolverine-build-thread.385920/post-7394380
See here
https://www.diyaudio.com/community/...he-wolverine-build-thread.385920/post-7394380
Hi guys,
I plan on building the Wolverine with the 4th group buy and I would want to use the time until then to think through some things and collect some information to set up everything appropriatly. Therefore I got some questions, excuse me already if they are somewhat redundant or stupid xD
Q1: Is there a good case for sale somewhere that fits the Wolverine? I already looked for defect amps but that can be kinda hard since i have no idea about what dimensions are suitable and if the cooling is appropriate.
Q2: Are there any good open source utility circuits like soft starter, speaker protection, etc available that fit the Wolverine? Ive seen the design from OmeEd in #3,667 and previous posts and Im very intersted in something like that, but dont know if that, or anything like this is available for use?
Q3: Currently Id aim for dual mono with 70V rails with 2x this 500VA toroid: https://sklep.toroidy.pl/en_US/p/TTSA0500-Transformer-AUDIO-TSA500VA-voltage-to-50-V/319
What capacity would be suitable for that kind of powersupply(s) and are there any specific caps/brands that you would recommend?
Thank you for your help and have a good start in the week!
Flo
I plan on building the Wolverine with the 4th group buy and I would want to use the time until then to think through some things and collect some information to set up everything appropriatly. Therefore I got some questions, excuse me already if they are somewhat redundant or stupid xD
Q1: Is there a good case for sale somewhere that fits the Wolverine? I already looked for defect amps but that can be kinda hard since i have no idea about what dimensions are suitable and if the cooling is appropriate.
Q2: Are there any good open source utility circuits like soft starter, speaker protection, etc available that fit the Wolverine? Ive seen the design from OmeEd in #3,667 and previous posts and Im very intersted in something like that, but dont know if that, or anything like this is available for use?
Q3: Currently Id aim for dual mono with 70V rails with 2x this 500VA toroid: https://sklep.toroidy.pl/en_US/p/TTSA0500-Transformer-AUDIO-TSA500VA-voltage-to-50-V/319
What capacity would be suitable for that kind of powersupply(s) and are there any specific caps/brands that you would recommend?
Thank you for your help and have a good start in the week!
Flo
1. Are you using EF3-3 or EF3-4 ? That will determine your case depth requirements. Take a look at Modushop - they have cases and options for UMS (EF3-3 with TO-3P outputs) and also wolverine EF3-4 specific predrilled heatsinks. I think minimum is the 4U/H165 case height for sufficient cooling - I could be wrong here others may interject.
2. https://diyaudiostore.com/collectio...speaker-turn-on-delay-and-dc-protector-boards, there are many others on this forum also
3. 71VDC rails with 500VA per channel should give you 200W/8 ohm , 360W/4 ohm. From the BOM, which you get when ordering the PCBs. You would order 50V AC transformer - but note you need to work out whether you need a centre tapped output 50-0-50V or separate outputs 50V x2.
I think the starting "rule of thumb" is 10,000uf per 100W into 8R, so 200w=20,000uf per rail per side is what I used, total 80,000uf. You could probably get away with 20,000uf per channel for a total of 40,000uf and not notice.
2. https://diyaudiostore.com/collectio...speaker-turn-on-delay-and-dc-protector-boards, there are many others on this forum also
3. 71VDC rails with 500VA per channel should give you 200W/8 ohm , 360W/4 ohm. From the BOM, which you get when ordering the PCBs. You would order 50V AC transformer - but note you need to work out whether you need a centre tapped output 50-0-50V or separate outputs 50V x2.
I think the starting "rule of thumb" is 10,000uf per 100W into 8R, so 200w=20,000uf per rail per side is what I used, total 80,000uf. You could probably get away with 20,000uf per channel for a total of 40,000uf and not notice.
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I believe that for a lot of us is better not to go over 38-40V in secondaries, so the DC voltage will stay under 63V , capacitors are much cheaper.
What is the advantage to have dual secondaries + dual bridge rectifiers VS center tap (or dual secondaries) +single bridge rectifier?
What is the advantage to have dual secondaries + dual bridge rectifiers VS center tap (or dual secondaries) +single bridge rectifier?
My Wolverine has 2X42V in secondaries 400-500VA each trafo 24.000 uf/80V per rail dual rectifiers about... 57-59VDC plays very well ...and after one year i check the bias again ......rock steady rich to 45mv and stabilize at 40-41mv ... and the dc offset 0.0063 and 0.0036mv.....
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Hey,
thanks for the feedback @mainframe99, of course I forgot to mention that I want to go for the EF3-4. I think the toroidy transformers have 2x50V (dual secondaries) so I would need to decide if single or dual bridge. Ive searched for the difference and ended in a thread on here that was exactly about the topic but still couldnt give me an answer lol. So Im joining @asuslover with the question dual rectifiers vs single rectifier? (taken that you can choose with a dual secondary transformer)
thanks for the feedback @mainframe99, of course I forgot to mention that I want to go for the EF3-4. I think the toroidy transformers have 2x50V (dual secondaries) so I would need to decide if single or dual bridge. Ive searched for the difference and ended in a thread on here that was exactly about the topic but still couldnt give me an answer lol. So Im joining @asuslover with the question dual rectifiers vs single rectifier? (taken that you can choose with a dual secondary transformer)
The center-tap won't be perfectly centered. That gives rise to a 60Hz component in the ripple.
The downside of dual diode bridges is that the diode losses are doubled.
Ed
The downside of dual diode bridges is that the diode losses are doubled.
Ed
Center tap - Any examples of that occurring? not disagreeing, in fact I tend to agree just be interesting to see
Yep, less rail loss with one rectifier.
Yep, less rail loss with one rectifier.
You can easily see the effects of a non-centered center tap in the supply ripple - every other peak will be higher.
Ed
Ed