Hi @richbandit
Thank you for taking the time to write your post and welcome to the discussion.
I agree I would love to hear more reviews from other members who have built this amplifier.
For now I believe there is a formal review written by @fireanimal attached to the 1st post of this thread. I also know of reviews written in the context of the thread written by @thimios @neilshop and @danieljw You may want to search there profiles for the related posts.
I would also encourage other members to write a review of the wolverine. I would be happy to attached it to the first post.
Hi @stuartmp
Many thanks for responding to my query.
Yes, I've seen those reviews and certainly they seem very promising, especially the one from @fireanimal.
As you say, I would also welcome any further reviews from those members that have completed their builds and have had chance to listen to the Wolverine 'in action', along with some realistic info about how it sounds. Whilst of course a huge amount of the enjoyment is in the build process (the 'I did that!' syndrome), the ultimate objective is to hopefully end up with a best-in-class sounding amplifier .....
That would greatly help any members who are interested but are currently 'on the fence' (like me, it seems!) to make that final decision to go for it!
Thanks again.
I can assure you that if you build this amplifier you will not be disappointed.
Thanks @fireanimal, your valued opinion is comforting to hear! Now where'd I leave that credit card ......
@fireanimal,
Kudos to you for your builds as well as the ancillary offerings you have for diy hobbyists who want to complete this build expeditiously. May I ask you what subjective differences in particular you heard between the Orchard Audio Class D designs, the Modulus designs by Tom C and this Wolverine amplifier build?
I own both Modulus amplifiers and Orchard Audio Class D as such I am quite interested in the differences. Please also describe your general audio setup, speakers (sensitivity), room size, SPL levels you listen to, etc…if you can.
And does anybody else know what are the Class A/AB ratings of this amplifier in 8 ohms? In other words, how many watts in Class A, prior to transitioning to Class AB? If it’s just a few milliwatts, no worries, it makes it primarily a Class B amplifier (Like Modulus 686, etc…). I understand the transition point is directly correlated with the bias current applied and the max output power (in Class AB) is directly correlated to the load as well as voltage at the rails after rectification.
Thanks again for your time,
Anand.
Kudos to you for your builds as well as the ancillary offerings you have for diy hobbyists who want to complete this build expeditiously. May I ask you what subjective differences in particular you heard between the Orchard Audio Class D designs, the Modulus designs by Tom C and this Wolverine amplifier build?
I own both Modulus amplifiers and Orchard Audio Class D as such I am quite interested in the differences. Please also describe your general audio setup, speakers (sensitivity), room size, SPL levels you listen to, etc…if you can.
And does anybody else know what are the Class A/AB ratings of this amplifier in 8 ohms? In other words, how many watts in Class A, prior to transitioning to Class AB? If it’s just a few milliwatts, no worries, it makes it primarily a Class B amplifier (Like Modulus 686, etc…). I understand the transition point is directly correlated with the bias current applied and the max output power (in Class AB) is directly correlated to the load as well as voltage at the rails after rectification.
Thanks again for your time,
Anand.
Hello- putting in my last order before getting started. Trying to match transistors as close as possible - a couple questions:
1) I don't have a matching jig for Q1 and Q2, for anyone that has built it would you consider selling me matched pairs? For health reasons this may be my last amp build otherwise I would looking into building a jig.
2) I've read some folks seeing differences in HFE between NPN/PNP driver and outputs, has anyone had luck sourcing ones that are closer together?
3) Based what's available I have MJE15034/15035 for drivers. 2SC5200/1943 are the cheapest outputs but not available in the same version, then NJW3281/1302 at around $85 and MJE4281/4302 at $105.
Thanks for any help and excited to get building!
Amp will start around 60v using transformers I already have, planning up get new transformers eventually and run closer to 70v.
1) I don't have a matching jig for Q1 and Q2, for anyone that has built it would you consider selling me matched pairs? For health reasons this may be my last amp build otherwise I would looking into building a jig.
2) I've read some folks seeing differences in HFE between NPN/PNP driver and outputs, has anyone had luck sourcing ones that are closer together?
3) Based what's available I have MJE15034/15035 for drivers. 2SC5200/1943 are the cheapest outputs but not available in the same version, then NJW3281/1302 at around $85 and MJE4281/4302 at $105.
Thanks for any help and excited to get building!
Amp will start around 60v using transformers I already have, planning up get new transformers eventually and run closer to 70v.
Thanks!
I use a Yamaha RX-A6A fed to a Minidsp Flex Balanced, which is my active crossover for my JBL Array 1400's. The JBL's have the low frequency crossover removed, and a couple mods on the HF crossover. My room is appox 1500 cu/ft and listening position is roughly 8 feet from the main speakers. I listen at levels anywhere between moderate and rock stadium depending on the music lol. This is also my main movie room as well, but no compromises were made for stereo listening.
For 6 or so months 4 channels of my Orchard build were used to power the JBL's. They sounded great, but lacked on power and gain. I could crank them, but not rock stadium. They would go into protection on my LF driver amps and would need power cycled. The stereo image was also good, very detailed but seemed to drift between the speakers.
Once I switched to the wolverine amps, I was honestly shocked at the difference. It's obvious with more wattage comes more SPL, but what really surprised me was the extra clarity at low levels, and when I do crank it, they do not hesitate. Have you every listened to High SPL distortion free music that is so clear that you forget how loud it actually is until someone tries to talk to you, and all you see is their lips moving....That's what I get now. Also the stereo image on 2 channel music is so focused between the speakers, I actually have got up to check the center speaker was actually off. Even at High levels, I get the full range of the soundtrack with ease, the dynamic range is incredible!
If you were to compare this amp to commercial offerings, I bet you wouldn't find anything that would beat it for less then 20k per channel. This amp measures better and flatter to 20khz then any I have seen anywhere, with ample gain and loads of watts.
The modulus 4 channel amp I built is only used for my Horn Subs, so I cannot give a subjective opinion on how they sound.
In all honesty I would not get hung up on the class A class A/AB thing. Been there done that. Just look at the distortion graphs from the wolverine, and tell me where the crossover distortion is, and how any Class A amps would even come close to it.
I have a matched quad C4883A/A1859A left with hfe 145/145/145/146 nnpp. Also about 100 pairs untested with more possible good matches. Where are you from?
Hello and welcome Richbandit. imo a high quality amplifier should not add any 'sound' at all. Just amplify (without adding any distortion), and offer a very low output impedance. The initial design as posted by Pete Ostripper on 22-03-2021 was very close to a blameless design as known from D. Self, adding an extra EF. Current design shows some improvements on top of that. Unfortunate the schematic is not made available to all, while I understand the reasons behind this, it makes discussion about the design quality somewhat difficult. Looking at the schematic, I am confident that it will suit my needs. As you know, a power amp is just one, important, part of an audio setup, the choice of speakers, and the way those are connected to the amps, will make an significant difference to the overall quality. A setup using active filtering is preferred by me and others.
Once the distortion testing is complete, I anticipate that the schematic will be made public within 2-3 weeks. Which should give people sitting on the fence enough time to review it before the 2nd group buy closes.
@fireanimal
Thanks for the response and subjective comments. On the contrary I am not really hung up on Class A/AB stuff other than interest in if the output stage on this Wolverine design is of high or low current bias (and if that is an option allowed). And yes, regarding measurements, I agree, the Modulus 686 I have is very low bias (frankly just <100 mW in Class A) and has exceptional measurements (ie no crossover distortion, etc…) in pretty much all parameters.
Best,
Anand.
Thanks for the response and subjective comments. On the contrary I am not really hung up on Class A/AB stuff other than interest in if the output stage on this Wolverine design is of high or low current bias (and if that is an option allowed). And yes, regarding measurements, I agree, the Modulus 686 I have is very low bias (frankly just <100 mW in Class A) and has exceptional measurements (ie no crossover distortion, etc…) in pretty much all parameters.
Best,
Anand.
Thank you RickRay.
Providing I understand the matter right.
Distorsion below noise @ 1 kHz, 1 W.
Is it possible to measure some difficult signals, like 220 Hz + 1 kHz @ 100 W ?
Providing I understand the matter right.
Distorsion below noise @ 1 kHz, 1 W.
Is it possible to measure some difficult signals, like 220 Hz + 1 kHz @ 100 W ?
Maybe if I get my measurement system sorted out. As you can see the 60Hz line is emphasised and all the odd harmonics to go with it. I'm 99% positive this is not the amp, it is my measurment system. I need to fix that before I post anything on here. Compare my harmonic numbers and distribution with fireanimals review in post #1 and they are very close, but he has none of the 60Hz with odd fundamnetals.
Anyone. I have the negative rail floating right now. Is it possible that the 60Hz and odd harmonics are a result of that zero volt rail floating? I will test myself when I get time running a wire from the zero rail to earth ground.