chicco_36 said:
Dear chicco_36,
I never made pictures of the inside. However, the 7BSST is in fact a bridged 4BSST, but offcourse with a couple of changes.
1: The powersupply rails are lowerd from 85 volt for the 4BSST tot 65 volt for the 7BSST.
2: Instead of two 600V/A transforems the 7BSST use one big (around 1500V/A) plitron transformer.
3:Instead of the 16x 5600uF capacitors of the 4BSST the 7BSST uses 16 (8 a amplifier side) 10000uF capacitors and that makes a solid 160000uF a monobloc!. This is one of the misstakes in the schematic's. There they say 1000uF each
the whole design is clever and power supply impedance is as low as possible. The capacitors are just 1" away from the outputstage!
Resume:
Bryston 4BSST:
85 volt +/-
5600 MFD x16 supply capacitance (total: 44800MFD a channel)
Bryston 7BSST:
65 volt +/-
10000 MFD x16 supply capacitance (total: 160000MFD a monobloc)
The only complain I have is a slight humm from the plitron transformers. But i can live with that. I can not praise the fantastic sound of the SST series enough. The older ST is no comparison (in sound).
Kind regards,
Bas
Hi Sebastiaan,
I haven't seen an SST model, just the old ones. That's what I meant when I said
I am happy to hear they are finally delivering a quality product. My past experience with them was opposite.
From some of the statements I've read, the key players haven't changed. I didn't expect the product to change. Beware of the straight "B" products. They are everything I've stated.
I have to say, stacking amps directly on top of each other isn't that smart. They are enduring more heat than they should. Your choice.
-Chris
I haven't seen an SST model, just the old ones. That's what I meant when I said
.
I am happy to hear they are finally delivering a quality product. My past experience with them was opposite.
From some of the statements I've read, the key players haven't changed. I didn't expect the product to change. Beware of the straight "B" products. They are everything I've stated.
I have to say, stacking amps directly on top of each other isn't that smart. They are enduring more heat than they should. Your choice.
-Chris
anatech said:
Dear Chris,
I'm agree here with you. I was never intereseted in Bryston amps. The old series sound horrible in my ears. The ST series had qualitiy's but never good enough in the mid-highs as I want. I never consider Bryston amps ever, till I get the change to try the 7BSST. After a search for 1,5 years to a decent amp I try many many amps (Classe, Jeff Rowland Mark Levinson etc.) and every amp have something I don't like. I'm a DIY-er but building my own amp is something that never gonna happen. I simply don't believe I can build something that can equals the bryston's. That say's more about me that about DIY in general
But to continue, after i try the 7BSST's a knew it in 5 minutes. This is it!. They drive the huge B&W matrix-800 system.Any way there is a lot changed in the Bryston company, and it is a really good and stable product now, with a great sound. I simply can not imaging that someone can dislike the sound of the SST design.
I know putting a lot of amps without space in a rack is not a good thing, but it is there choice and there is no more space. There is a big airconditionar pipe in the machineroom behind the equipment.
A last word. I really like the low end to from the SST design, it is so controlled and tight. But I have to admit if you want real chestslamming lowend that's still tight then try a Crown k2 on the low's only. awsome!!
With kind regards,
Bas
Hi Bas,
I guess the size of the power service is impressive. That and a couple tons of air conditioning and you're okay.
Going to a toroid forced them to block DC. EI cores aren't as sensitive as toroids to DC components.
I guess Mr Taylor fixed their bias problem as well. I see that as one of the old amps biggest problems for reliability. Your friend touring would not still have an original amp. The chassis used to tear across the front at the bottom, causing the face to come off. Almost as funny as seeing a Yamaha P2200 dropped on it's face (big transformer tries to get out through the meters).
-Chris
I guess the size of the power service is impressive. That and a couple tons of air conditioning and you're okay.
Going to a toroid forced them to block DC. EI cores aren't as sensitive as toroids to DC components.
I guess Mr Taylor fixed their bias problem as well. I see that as one of the old amps biggest problems for reliability. Your friend touring would not still have an original amp. The chassis used to tear across the front at the bottom, causing the face to come off. Almost as funny as seeing a Yamaha P2200 dropped on it's face (big transformer tries to get out through the meters).
-Chris
hihiih
Dear Chris,
My friend still have a original 4BST. But the amp is fixed on the bottem of his 19" rack. So the front doesn't have carry the whole amps weight.
I'm a bassplayer to, And I have to admit, I prefer the Crown K2 for live apllication's. I'm inlove with the bass performance of the K2. But my friend is more a melodic player then me (more high notes) and he likes the harmonic texture of the Bryston so much.
The first wrong issue with the old Bryston's is the open single turn cheapass potentionmeter for bias adjustment. This kind of parts you never see anymore in a bryston SST amp. Now they have nice closed multiturn pot's.
The bias problem is fixed, and the bias circuit is not comparible with the older bryston's. Mr. Taylor is one of the greatest step's for the company! Since he is involved I started to like theyr sound more and more. It are the russel's that invented the quad complimentary circuit, but now many years later the circuit is (finaly) optimalized.
You said "Going to a toroid forced them to block DC. EI cores aren't as sensitive as toroids to DC components" that is true, but not many company's do something to block DC from the mains. They simply don't care. I never see this before. Comparible is the DC offset killer made by PS audio. Is basicly the same circuit, but you buy it as a sperate plug in for many dollars
To bad you live so far from me, else I know for sure I can convince you when you here them on the huge matrix-800's .
Kind regards,
Bas
Dear Chris,
My friend still have a original 4BST. But the amp is fixed on the bottem of his 19" rack. So the front doesn't have carry the whole amps weight.
I'm a bassplayer to, And I have to admit, I prefer the Crown K2 for live apllication's. I'm inlove with the bass performance of the K2. But my friend is more a melodic player then me (more high notes) and he likes the harmonic texture of the Bryston so much.
The first wrong issue with the old Bryston's is the open single turn cheapass potentionmeter for bias adjustment. This kind of parts you never see anymore in a bryston SST amp. Now they have nice closed multiturn pot's.
The bias problem is fixed, and the bias circuit is not comparible with the older bryston's. Mr. Taylor is one of the greatest step's for the company! Since he is involved I started to like theyr sound more and more. It are the russel's that invented the quad complimentary circuit, but now many years later the circuit is (finaly) optimalized.
You said "Going to a toroid forced them to block DC. EI cores aren't as sensitive as toroids to DC components" that is true, but not many company's do something to block DC from the mains. They simply don't care. I never see this before. Comparible is the DC offset killer made by PS audio. Is basicly the same circuit, but you buy it as a sperate plug in for many dollars
To bad you live so far from me, else I know for sure I can convince you when you here them on the huge matrix-800's
.Kind regards,
Bas
Bryston amplifiers
Please note the following. The bryston amplifiers use a combination of emitter follower (EF) and common emitter (CFP) output devices.
The EF has only current gain and all the base-emitter junctions in the output darlingtons must be compensated by the Vbe multiplier.
The CFP stage has both current and voltage gain (yes they are in a local feedback loop) BUT the base-emitter juctions are outside the thermal loop and ONLY the drivers' VBE must be monitored.
So there is a contradiction here. The Vbe mulitplier is fighting two different output topologies.
All Bystons have excessive crossover notch due to this problem. Secondly examine their Vbe mulitipliers, they are of the most simple form (from model to model there are some small changes) but the single transistor type cannot compensate for thermal changes in the O/P stages and also cannot keep the idle current constant. Note the trimmer in this Vbe multiplier, if the wiper lifts (a common issue with trimmers) then the Vbe goes open and poof goes your outputs!!!
Basically as I said before the circuit is crude and has too much open loop gain due to the extra stage used before the VAS stage.
They will NEVER solve their thermal issues with both EF and CFP in the output stages as the two topologoes do NOT like to work together
Steve
Zed Audio
Please note the following. The bryston amplifiers use a combination of emitter follower (EF) and common emitter (CFP) output devices.
The EF has only current gain and all the base-emitter junctions in the output darlingtons must be compensated by the Vbe multiplier.
The CFP stage has both current and voltage gain (yes they are in a local feedback loop) BUT the base-emitter juctions are outside the thermal loop and ONLY the drivers' VBE must be monitored.
So there is a contradiction here. The Vbe mulitplier is fighting two different output topologies.
All Bystons have excessive crossover notch due to this problem. Secondly examine their Vbe mulitipliers, they are of the most simple form (from model to model there are some small changes) but the single transistor type cannot compensate for thermal changes in the O/P stages and also cannot keep the idle current constant. Note the trimmer in this Vbe multiplier, if the wiper lifts (a common issue with trimmers) then the Vbe goes open and poof goes your outputs!!!
Basically as I said before the circuit is crude and has too much open loop gain due to the extra stage used before the VAS stage.
They will NEVER solve their thermal issues with both EF and CFP in the output stages as the two topologoes do NOT like to work together
Steve
Zed Audio
Steve,
Are you of HiFonics? If so, you are the producer of my favorite auto amplifiers of years ago (the original thor, odin, pluto,hercules,,etc). I worked with them professoinally for years and never saw a single failure. Quite a good design... and it used to make me money. Thanks. If I have it all wrong I just wasted a few pixels...
Regards,
Marc
Bryston
Dear Marc,
Yes that is me. I designed all those old school Hifonics, Autorek, Rodek, Lanzar, Nakamichi etc.
See our new Zed amps at www.zedaudio.com
Steve
Dear Marc,
Yes that is me. I designed all those old school Hifonics, Autorek, Rodek, Lanzar, Nakamichi etc.
See our new Zed amps at www.zedaudio.com
Steve
This thread is funny.
Bryston is a bad design, can't sound good in spite of selling
the same product for decades.
Krell KSA is another bad design that propells Krell to superstar
status.
Only the old school designs from Leach and Ampzilla are good.
Richard Clark doesn't allow you to bring your own amp so this variable
automatically discredits his works and works of other industry
professionals that share the same views.
Bryston is a bad design, can't sound good in spite of selling
the same product for decades.
Krell KSA is another bad design that propells Krell to superstar
status.
Only the old school designs from Leach and Ampzilla are good.
Richard Clark doesn't allow you to bring your own amp so this variable
automatically discredits his works and works of other industry
professionals that share the same views.
OK, Steve, so you don't like the Bryston. That's fair enough, it is a free world. But your comments aren't going to stop the rest of us having a go, whatever you say.
So by all means chip in with constructive comments as we progress, but your personal dislike of the circuit isn't going to stop the rest of us building it, so please refrain from non-constructive posting.
Thanks.
So by all means chip in with constructive comments as we progress, but your personal dislike of the circuit isn't going to stop the rest of us building it, so please refrain from non-constructive posting.
Thanks.
thylantyr said:
Dear,
Ampzilla is no comparison with the Bryston SST in mid-high harmonic freedom of sound! I heard the blue mono's while ago and had the change to compare with a Classe CA-2200 and a Bryston 14BSST. The ampzilla let you think everything is so detailed, but in fact brass sound nosy and don't have te freedom it sould be. For example hear a brass section hit a A7#5 chord. The trombone plays the A the trumpet the C# en so on. On so many amps you just hear the TETT! of the whole section. Also the ampzilla. The SST let jou hear the individual character of each cupper instrument in the right harmonic texture.
Non of the SST meassure's show's any bad thing. The show over and over agian that they do such a good job! (not for the ST series).
The Vbe multiplier works way different then you tell us. Take a look at their schematic for the SST (not the ST!!!!) What do you think they want to get al the amplifiers back for reapair in the future 20 years?
If the design is so bad, why does it sounds so good?? I trust my ears, and I know the SST design is way to go in sound!
I really doupt if the bryston haters ever listenend to a SST design....
Regards,
Bas
Re: Bryston
Sorry to digress but....
As soon as my a/d/s/ P640.2 dies or is stolen I will give the Leviathan a go. VERY impressive build and layout.
Ok, back to the thread @ hand..
I have read a lot of posts saying the Bryston's are unreliable (yet they back their products with the BEST warranty in the industry), and don't sound very good (Yet they are found in recording, live and commercial venues EVERYWHERE).
Bryston is (and always has been) a solid company who, like every other company, is steadily progressing with technology and time.
The issue with this thread is that in cloning a Bryston we would be cloning and trying to improve a current production model.
Where as in the Krell and Leach clones they were old models or models not in production.
So the question is.. Are we are we cloning a current, admired product instead of buying one from the manufacturer, or are we brain storming for ideas on how to improved the current product for the company?
Either way, unless an older model is cloned we are certainly breaking the tradition of taking an older, proven design and recreating and improving upon it.
I still love my original 3 & 4 b. I am happy just to clone them with better parts and circuit execution.
My 2 cents.
MOER said:
Sorry to digress but....
As soon as my a/d/s/ P640.2 dies or is stolen I will give the Leviathan a go. VERY impressive build and layout.
Ok, back to the thread @ hand..
I have read a lot of posts saying the Bryston's are unreliable (yet they back their products with the BEST warranty in the industry), and don't sound very good (Yet they are found in recording, live and commercial venues EVERYWHERE).
Bryston is (and always has been) a solid company who, like every other company, is steadily progressing with technology and time.
The issue with this thread is that in cloning a Bryston we would be cloning and trying to improve a current production model.
Where as in the Krell and Leach clones they were old models or models not in production.
So the question is.. Are we are we cloning a current, admired product instead of buying one from the manufacturer, or are we brain storming for ideas on how to improved the current product for the company?
Either way, unless an older model is cloned we are certainly breaking the tradition of taking an older, proven design and recreating and improving upon it.
I still love my original 3 & 4 b. I am happy just to clone them with better parts and circuit execution.
My 2 cents.
Bryston
Guys build whatever design you want.
I was asked to reply to this original post
I only pointed out what I see as potential problems. I have worked on Bryston amplifiers for many years.
I also quoted on a couply of well known and good designs.
There are many companies in both the home and car stereo worlds who sell product that is not very good and yet they have managed to keep selling them for years.
Soundstream had a great marketing company but their car amplifiers were bad - why? they tried to use the TIP142/147 Darlington pairs with only 0.1 ohm emitter resistors. They sold their amplifiers for nearly 10 years, built a nice company but had massive failures on their amplifiers. Try build an output stage with these devices and 0.1 ohm emitter resistors and see how far you go - nowhere. These Darlingtons have horrible Vbe characteristics and the ONLY way to keep them alive is to use say 1 ohm emitter resistors each bypassed with a simple high speed diode.
This allows you to bias them for no notch and still keep them thermally stable
These devices were the downfall of Soundstream amplifiers as they used the same topology for pretty much all their amps. (I repaired enough of them).
I just repaired a high end amplifier from Germany called B*** and it is a 100w/ch amplifier which sells for nearly $1K and it is very well made and uses IRF540N N-channel mosfets in a quasi-complementary circuit with NO thermal compensation. A truly crude amplifier that they manage to con the public into believing that it is a high end amplifier just because they sell it for lots of dough!!!
The home arena is no different. There are many fine designers out there, Pass, Nesterovik, Bongiorno to name a few BUT there are many many more pretenders who build gear that is so so and not that great for astronomical prices.
Guys build whatever design you want.
I was asked to reply to this original post
I only pointed out what I see as potential problems. I have worked on Bryston amplifiers for many years.
I also quoted on a couply of well known and good designs.
There are many companies in both the home and car stereo worlds who sell product that is not very good and yet they have managed to keep selling them for years.
Soundstream had a great marketing company but their car amplifiers were bad - why? they tried to use the TIP142/147 Darlington pairs with only 0.1 ohm emitter resistors. They sold their amplifiers for nearly 10 years, built a nice company but had massive failures on their amplifiers. Try build an output stage with these devices and 0.1 ohm emitter resistors and see how far you go - nowhere. These Darlingtons have horrible Vbe characteristics and the ONLY way to keep them alive is to use say 1 ohm emitter resistors each bypassed with a simple high speed diode.
This allows you to bias them for no notch and still keep them thermally stable
These devices were the downfall of Soundstream amplifiers as they used the same topology for pretty much all their amps. (I repaired enough of them).
I just repaired a high end amplifier from Germany called B*** and it is a 100w/ch amplifier which sells for nearly $1K and it is very well made and uses IRF540N N-channel mosfets in a quasi-complementary circuit with NO thermal compensation. A truly crude amplifier that they manage to con the public into believing that it is a high end amplifier just because they sell it for lots of dough!!!
The home arena is no different. There are many fine designers out there, Pass, Nesterovik, Bongiorno to name a few BUT there are many many more pretenders who build gear that is so so and not that great for astronomical prices.
I agree, there are people that sell under-par kit for extortionate prices. And if i was specc-ing kit for a studio or tour, or even just a friend's home install, then those issues that you raise would be vital.
But for DIYers, the priorities are slightly different. To us, the main expense is time, and as we do it for the love, then this is not really an issue. We build something, use it for a while, then invariably decide to build something new. If an amp proves unreliable, or doesn't sound so good, then it will get recycled sooner rather than later. And if you add the fact in that this is an interesting topology, then you're on to a winner.
At least that's the way that I see it anyway!
But for DIYers, the priorities are slightly different. To us, the main expense is time, and as we do it for the love, then this is not really an issue. We build something, use it for a while, then invariably decide to build something new. If an amp proves unreliable, or doesn't sound so good, then it will get recycled sooner rather than later. And if you add the fact in that this is an interesting topology, then you're on to a winner.
At least that's the way that I see it anyway!
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