Searching on the Diyaudio site also googling the web pages related amplifiers, I wondered why no one showed any interest in cloning Bryston amps. They are not just ordinary audiophile me too amps, but are excellent choice amongst professionals, were building quality and reliability are sometimes more important then the good sound. I will add great reviews in magazines; they are on recommended list in “Stereophile” for last decade, not to mention their original output stage and excellent spec.
Good reasons for me to clone one of these…
I will go for the “simplest” model, 3B SST, which have two output pairs per channel (MJL21193, 21194), 150watts into 8 ohms, 250 watts into 4 ohms. For me it’s more then enough power, and I don’t like amps with grater number of output transistors, sound wise.
From my research, other models have extra PCB with two more pairs per channel so anyone who wish my go for more power. From one older test in “Stereophile”(October 96), 3B ST has two toroidal transformers rated at 225 VA, and one 10000uF/63V cap per rail, 4 in total. I think the new model is very similar or the same. Rails are +- 55Volts DC.
According previous mentioned “Stereophile” issue, Stuart Taylor had great work to redesign older pcb’s and at the and he managed to lower the noise and THD a lot. That means we must design really good pcb with all the help from all experienced members.
Some usable pictures from `real thing` will be more then helpful!
All schematics can be downloaded at official Bryston site; also there can be found other interesting stuff like explanations about their Quad-Complementary output section.
Everyone opinions are welcome!
Best regards,
Chicco
Good reasons for me to clone one of these…
I will go for the “simplest” model, 3B SST, which have two output pairs per channel (MJL21193, 21194), 150watts into 8 ohms, 250 watts into 4 ohms. For me it’s more then enough power, and I don’t like amps with grater number of output transistors, sound wise.
From my research, other models have extra PCB with two more pairs per channel so anyone who wish my go for more power. From one older test in “Stereophile”(October 96), 3B ST has two toroidal transformers rated at 225 VA, and one 10000uF/63V cap per rail, 4 in total. I think the new model is very similar or the same. Rails are +- 55Volts DC.
According previous mentioned “Stereophile” issue, Stuart Taylor had great work to redesign older pcb’s and at the and he managed to lower the noise and THD a lot. That means we must design really good pcb with all the help from all experienced members.
Some usable pictures from `real thing` will be more then helpful!
All schematics can be downloaded at official Bryston site; also there can be found other interesting stuff like explanations about their Quad-Complementary output section.
Everyone opinions are welcome!
Best regards,
Chicco
Bryston amps
Not very good amplifiers. Examine the circuits closely. The differential amplifiers have NO local feedback and have no constant current sources driving them but simply resistors to a zener diode. The VAS stages are rather crude also with minimal local feedback and yes they do give low measured THD due to their massive open loop gain and then the tons of global feedback applied. The VAS is a two stage affair with cascaded common emitter amplifiers which further increases open loop gain.
We have worked on sevral models of these amplifiers and found instability in driving reactive loads. The amplifiers are marginally stable.
The cookiest idea is having both emitter followers and collector followers in the output stages. For what reason? The EF configuration gives slightly worse saturation than CF but who cares , add 1-2 volts of rail. I have nothing against CFP output stages BUT they must be compensated with local feedabck to keep them stable. They do have lower measured THD than EF outputs but who cares. It is the nature of the distortion that we care about, not how much.
The use of coils in the speaker circuit is further proof of the unstable nature of these circuits.
Not very good amplifiers. Examine the circuits closely. The differential amplifiers have NO local feedback and have no constant current sources driving them but simply resistors to a zener diode. The VAS stages are rather crude also with minimal local feedback and yes they do give low measured THD due to their massive open loop gain and then the tons of global feedback applied. The VAS is a two stage affair with cascaded common emitter amplifiers which further increases open loop gain.
We have worked on sevral models of these amplifiers and found instability in driving reactive loads. The amplifiers are marginally stable.
The cookiest idea is having both emitter followers and collector followers in the output stages. For what reason? The EF configuration gives slightly worse saturation than CF but who cares , add 1-2 volts of rail. I have nothing against CFP output stages BUT they must be compensated with local feedabck to keep them stable. They do have lower measured THD than EF outputs but who cares. It is the nature of the distortion that we care about, not how much.
The use of coils in the speaker circuit is further proof of the unstable nature of these circuits.
Hi MOER,
You wrote:
“Bryston amps
Not very good amplifiers.”
Your experience is based from looking in the schematics, servicing them, or owning one for your listening pleasure?
I’m not educated in electronics enough to analyze schematics like you did, but I had opportunity to listen 3B ST and 4B ST in two different systems, driving B&W 802 matrix and Martin Logan SL3. Sound was excellent, and both owners independently told me that after changing a lot of amps, they finally settled with Brystons. Neither of them had “instability problems”.
You wrote:
“We have worked on several models of these amplifiers and found instability in driving reactive loads. The amplifiers are marginally stable.”
“The use of coils in the speaker circuit is further proof of the unstable nature of these circuits.”
As I understand, every Bryston amp has 100 hours burn in at full power before living the factory. Not to mention 20-year transferable warranty…
Will they offer that kind of service for “unstable” or “marginally stable” products? I don’t think so.
They did sell amps in professional market where is a lot of abusing, but from what I read, Bryston amps are very popular amongst professionals.
I will also add that 3B SST selling price in UK is 1725 pounds, about 2500 euros. What’s wrong if one can clone it for 10% of that price???
At the end, can you point other interesting amp worth cloning (bipolar design, two power transistor pairs per channel, which is more stable but more important, with better sound quality) ???
Best regards,
Chicco
You wrote:
“Bryston amps
Not very good amplifiers.”
Your experience is based from looking in the schematics, servicing them, or owning one for your listening pleasure?
I’m not educated in electronics enough to analyze schematics like you did, but I had opportunity to listen 3B ST and 4B ST in two different systems, driving B&W 802 matrix and Martin Logan SL3. Sound was excellent, and both owners independently told me that after changing a lot of amps, they finally settled with Brystons. Neither of them had “instability problems”.
You wrote:
“We have worked on several models of these amplifiers and found instability in driving reactive loads. The amplifiers are marginally stable.”
“The use of coils in the speaker circuit is further proof of the unstable nature of these circuits.”
As I understand, every Bryston amp has 100 hours burn in at full power before living the factory. Not to mention 20-year transferable warranty…
Will they offer that kind of service for “unstable” or “marginally stable” products? I don’t think so.
They did sell amps in professional market where is a lot of abusing, but from what I read, Bryston amps are very popular amongst professionals.
I will also add that 3B SST selling price in UK is 1725 pounds, about 2500 euros. What’s wrong if one can clone it for 10% of that price???
At the end, can you point other interesting amp worth cloning (bipolar design, two power transistor pairs per channel, which is more stable but more important, with better sound quality) ???
Best regards,
Chicco
Attachments
Bryston
Dear Chicco,
Yes I look at them from an engineering standpoint and also have compared them in my home system to others. I have a double blind A-B set up that can be installed in my speaker leads. I do this only on the mids and highs.
My subs are servo controlled and not easily A-B compared.
I have Infinity Gammas which are not easy loads to drive. I also always keep an oscilliscope connected so I can see what is going on.
I did a comparison about 6 months ago with a Bryston 4B, an original GAS Ampzilla from 1975 and my own McIntosh MI350 mono tube amplifiers.
The GAS was streets ahead of the 4B and it was quite easy to pick it out time again. The 4B sounds like Crown amplifiers, grainy, clinical and edgy.......... why you may ask? Well high open loop gain massive global feedback low low THD designs tend to sound this way.
The GAS is the opposite in design. Low global feedback, lots of local feedback loops, short signal path.
I am sure the bottom end of the 4B is good due to big power supplies and high damping factor (which I do not place much credence on anyway. Just add in the series R of the speaker coil and effective damping factor becomes 1.3!!!
The 4B against the MI350s was not even a competition. The Macs were light years ahead, yes I am comparing a tube amplifier to a solid state nut never the less. The Macs were also better than the GAS.
There are many other great designs to copy at 10% of the cost I know as I am a manufacturer of amplifiers.
The Leach design is streets ahead of the 4B or 3B just to name one. Copy the original GAS Ampzilla it hold it's own against most modern day designs anyway.
Regards
Steve
Dear Chicco,
Yes I look at them from an engineering standpoint and also have compared them in my home system to others. I have a double blind A-B set up that can be installed in my speaker leads. I do this only on the mids and highs.
My subs are servo controlled and not easily A-B compared.
I have Infinity Gammas which are not easy loads to drive. I also always keep an oscilliscope connected so I can see what is going on.
I did a comparison about 6 months ago with a Bryston 4B, an original GAS Ampzilla from 1975 and my own McIntosh MI350 mono tube amplifiers.
The GAS was streets ahead of the 4B and it was quite easy to pick it out time again. The 4B sounds like Crown amplifiers, grainy, clinical and edgy.......... why you may ask? Well high open loop gain massive global feedback low low THD designs tend to sound this way.
The GAS is the opposite in design. Low global feedback, lots of local feedback loops, short signal path.
I am sure the bottom end of the 4B is good due to big power supplies and high damping factor (which I do not place much credence on anyway. Just add in the series R of the speaker coil and effective damping factor becomes 1.3!!!
The 4B against the MI350s was not even a competition. The Macs were light years ahead, yes I am comparing a tube amplifier to a solid state nut never the less. The Macs were also better than the GAS.
There are many other great designs to copy at 10% of the cost I know as I am a manufacturer of amplifiers.
The Leach design is streets ahead of the 4B or 3B just to name one. Copy the original GAS Ampzilla it hold it's own against most modern day designs anyway.
Regards
Steve
Hi Chicco,
I have to agree with MOER here. I've serviced them and listened to them. Nothing special at all. The funny output stage is something Bryston cooked up in a garage years ago. It's part of what a Bryston is and they will not change it. I don't feel they are as reliable as they could be. Possibly the lastest ones are better? I don't know.
I would not bother building an ST or original. A complete waste of a good heatsink. There are other things that sound way better, why not go with an amp from this forum in that case.
The Bryston product would be good to study. I'd approch them from that angle.
-Chris
I have to agree with MOER here. I've serviced them and listened to them. Nothing special at all. The funny output stage is something Bryston cooked up in a garage years ago. It's part of what a Bryston is and they will not change it. I don't feel they are as reliable as they could be. Possibly the lastest ones are better? I don't know.
I would not bother building an ST or original. A complete waste of a good heatsink. There are other things that sound way better, why not go with an amp from this forum in that case.
The Bryston product would be good to study. I'd approch them from that angle.
-Chris
I would give this project a go for the same reason I did the Krellclones, why not? Yes, it may have issues but half the fun of this hobby is trying things out, and certainly, in the UK, Brystons are relatively rare on the S/H market.
Let's face it, the expensive lumps are the case and psu, both of which could be reused for other projects if the Bryston is not deemed worthy. But if you don't build one, you don't know...
Let's face it, the expensive lumps are the case and psu, both of which could be reused for other projects if the Bryston is not deemed worthy. But if you don't build one, you don't know...
I've lived with many amps over the years including 3 different Brystons. IMHO there have been very few amps that exceeded the 3B which is not as good sounding as the 4B. The 4B was a bit "edgy" when I first got it hooked up to my speakers but that only lasted a few weeks. I would not characterize its sound as grainy or edgy now. Clinical, maybe, but it also has very good ambience and solid bass. It will expose poor recordings. I think accurate is a better discription in this case.
Reliable? Heck, each of them were/are workhorses that will not quit. And by continuing to offer a 20 year transferable warranty, you know that Bryston knows it as well.
In short, there are far more inferior sounding amps out there than there are better sounding amps to clone.
Reliable? Heck, each of them were/are workhorses that will not quit. And by continuing to offer a 20 year transferable warranty, you know that Bryston knows it as well.
In short, there are far more inferior sounding amps out there than there are better sounding amps to clone.
I think every company has "A unique design approach" which earns him a distinguished identity from rest of the traditional designs or company's and therefore it would not leave that foremost feature so easily which is crafted or created or invented by him with hardwork...whether that feature is good or bad, but when you workhard to achieve something, then its very difficult to believe that the thing at which you are working is worth nothing...it takes a lot of time to accept....but again Time is the greatest Healer...
K a n w a r
I had couple 7BSST while back, bought brand new. Both of them were not functioning when first hook up and sent back to the factory to be service.
I was told the control cable some how got disconnect in one; and the other one had a bad resistor. They agree to pay for the shipping back to them also.
Got them back and one amp worked fine and the other still were not, so back it went. After about 4 weeks, I got them both working. They sound ok to me and ran very hot.
I sold them after 4 weeks.
For the 20 years warranty, it is good. But what a pain in rear to log them around and no music for a while.
I was told the control cable some how got disconnect in one; and the other one had a bad resistor. They agree to pay for the shipping back to them also.
Got them back and one amp worked fine and the other still were not, so back it went. After about 4 weeks, I got them both working. They sound ok to me and ran very hot.
I sold them after 4 weeks.
For the 20 years warranty, it is good. But what a pain in rear to log them around and no music for a while.
Double blind test
My comparisions were done double blind A-B with someone else switching. In each case I matched the gains of all the amplifiers to less than 0.1dB. I used one of my Audio Precision System One's to do this so that gain would not be the issue.
The Krell KSA series has similar problems to the Brystons, high open loop gain , massive amounts of global feedback, no degeneration in the dual differentials and early versions had their diff pairs driven by simple resistors from the opposite rails.
Regards
Steve
My comparisions were done double blind A-B with someone else switching. In each case I matched the gains of all the amplifiers to less than 0.1dB. I used one of my Audio Precision System One's to do this so that gain would not be the issue.
The Krell KSA series has similar problems to the Brystons, high open loop gain , massive amounts of global feedback, no degeneration in the dual differentials and early versions had their diff pairs driven by simple resistors from the opposite rails.
Regards
Steve
Re: Double blind test
you should consider entering some of those amp dbx tests. One of them will give you 10K for being able to tell amps apart. You could make very good living by just going through the tests.
So far, I haven't heard anyone winning but you sure sound like the 1st person who can crack it.
MOER said:
you should consider entering some of those amp dbx tests. One of them will give you 10K for being able to tell amps apart. You could make very good living by just going through the tests.
So far, I haven't heard anyone winning but you sure sound like the 1st person who can crack it.
I've owned the 3b and 4b to drive the B&W Matrix 805's via 8' bi-wired Kimber 4TC.
Had numerous visitors meet at my house to go window shopping at the Hi-Fi salons.
We would all agree that my "budget system" beat the pants off the multi kilo-buck systems we would audition. Grant it set up and system matching played a huge part in it.
The last Bryston was eventually replaced with a JRDG Model 2 when I eventually saved enough money.
Way better imaging and sound, but a little less involving. The Bryston's just boogied!
Had numerous visitors meet at my house to go window shopping at the Hi-Fi salons.
We would all agree that my "budget system" beat the pants off the multi kilo-buck systems we would audition. Grant it set up and system matching played a huge part in it.
The last Bryston was eventually replaced with a JRDG Model 2 when I eventually saved enough money.
Way better imaging and sound, but a little less involving. The Bryston's just boogied!
Chicco,
The great thing about this forum is that every viewpoint, preference and personality type is well represented. You'll not lack from a representative cross-section of opinions. Take them all into consideration, but also view each one with a healthy skepticism.
Let me echo some of the others with my advice: If the Bryston is what interests you, then build it! Is it my first choice of an amp to build? No, I've built a few DIY amps now and I haven't built a Bryston yet, as my personal preferences tend towards the Nelson Pass and Charles Hansen approaches to amplifiers, but I have also dabbled with chip amps and made a brief (and so far unsuccesful) foray into tubes. But I know several guys who think that single ended tube triode amps are the only worthwhile effort, and others who believe that chipamps are the holy grail. Best of all, I've heard amps from each class, and can say that there are very fine sounding representations from each approach.
Lastly, of the DIY'ers I personally know, no-one has built only one amp. The amount you will learn, and the fun you'll have just going through the process will make your efforts worthwhile no matter which amp you choose to build, and even if it doesn't turn out to be the amp to end all amps, you can be assured that by the time you finish it will sound very good and make you happy.
Cheers, Terry
EDIT:
Sorry Chicco, I just realized that you have more than a bit of experience already at building an amp. Pleaase feel free to disregard the more patronizing sections of my post and accept my apologies!
The great thing about this forum is that every viewpoint, preference and personality type is well represented. You'll not lack from a representative cross-section of opinions. Take them all into consideration, but also view each one with a healthy skepticism.
Let me echo some of the others with my advice: If the Bryston is what interests you, then build it! Is it my first choice of an amp to build? No, I've built a few DIY amps now and I haven't built a Bryston yet, as my personal preferences tend towards the Nelson Pass and Charles Hansen approaches to amplifiers, but I have also dabbled with chip amps and made a brief (and so far unsuccesful) foray into tubes. But I know several guys who think that single ended tube triode amps are the only worthwhile effort, and others who believe that chipamps are the holy grail. Best of all, I've heard amps from each class, and can say that there are very fine sounding representations from each approach.
Lastly, of the DIY'ers I personally know, no-one has built only one amp. The amount you will learn, and the fun you'll have just going through the process will make your efforts worthwhile no matter which amp you choose to build, and even if it doesn't turn out to be the amp to end all amps, you can be assured that by the time you finish it will sound very good and make you happy.
Cheers, Terry
EDIT:
Sorry Chicco, I just realized that you have more than a bit of experience already at building an amp. Pleaase feel free to disregard the more patronizing sections of my post and accept my apologies!
Hi to all!
I was left without PC and internet connection for almost two weeks, so, sorry to all.
I see more negative opinions than positive; I guess Bryston will wait to see some of their amps cloned … for a while.
Terry (metalman),
No need for apologie, my diy interest started when I firstly discovered this site years ago. We all learning every day and always be different opinions about one particular amp, like fets vs bipolars, or tubes vs solid state.
Like pinkmouse stated, we can always reuse case and PSU, which are most expensive parts of any amp.
Must be something more to build than Aleph, KSA-50, gainclone or Leach…
Best regards,
Chicco
I was left without PC and internet connection for almost two weeks, so, sorry to all.
I see more negative opinions than positive; I guess Bryston will wait to see some of their amps cloned … for a while.
Terry (metalman),
No need for apologie, my diy interest started when I firstly discovered this site years ago. We all learning every day and always be different opinions about one particular amp, like fets vs bipolars, or tubes vs solid state.
Like pinkmouse stated, we can always reuse case and PSU, which are most expensive parts of any amp.
Must be something more to build than Aleph, KSA-50, gainclone or Leach…
Best regards,
Chicco
Hey Chicco,
If you are curious about a Bryston, then build one. I bet you do a better job. The PCB's are on the Bryston site as well as the schematics.
Just by matching the parts you'll get a better amp. Possibly you will use some real heatsinks. The construction of a Bryston involved each channel as a module, interchangable. They used card connectors to make all the connections. Don't do that. Normal wiring will make a better amp.
As a tweak, you may want to redo the bias circuit. That way the bias will be stable and the amp will sound much better when first turned on.
-Chris
If you are curious about a Bryston, then build one. I bet you do a better job. The PCB's are on the Bryston site as well as the schematics.
Just by matching the parts you'll get a better amp. Possibly you will use some real heatsinks. The construction of a Bryston involved each channel as a module, interchangable. They used card connectors to make all the connections. Don't do that. Normal wiring will make a better amp.
As a tweak, you may want to redo the bias circuit. That way the bias will be stable and the amp will sound much better when first turned on.
-Chris
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