Hi Johnny2Bad,
Mr. Tanner was very displeased with me at the time. Let's just say I know those amps better than you ever could. I fixed many and know exactly what they did right, and what they did wrong. I saw many that blew up on their own operating into 8 ohm loads at sane levels.
Did you have any of those face plates tear or come right off in the road case? How about dead power switches? Did they sound good when first turned on by chance? I know why they didn't, just so you don't answer that question incorrectly.
As bad as those amplifiers were, their later products became well engineered with the arrival of S.T. I like the current products, so I'm not on a hate Bryston trip. I'm just telling you the truth.
-Chris
Mr. Tanner was very displeased with me at the time. Let's just say I know those amps better than you ever could. I fixed many and know exactly what they did right, and what they did wrong. I saw many that blew up on their own operating into 8 ohm loads at sane levels.
Did you have any of those face plates tear or come right off in the road case? How about dead power switches? Did they sound good when first turned on by chance? I know why they didn't, just so you don't answer that question incorrectly.
As bad as those amplifiers were, their later products became well engineered with the arrival of S.T. I like the current products, so I'm not on a hate Bryston trip. I'm just telling you the truth.
-Chris
Not sure what your clients were doing with them, we sold 20~30 per year and never saw a single one come back for service. I'm referring to the 2nd iteration of the 2/3/4B, the ones sold in the late 70's. No power switch failures that i'm aware of. Some bent rackmount ears, no breaks. I don't know about "least expensive parts you could buy" but the retail prices were quite reasonable ($450/800/1200).
Yes, they needed a warm-up period to settle in sound wise. The best sounding of the series was the 2B, the 3B the worst.
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The 3B was nearly identical to the 4B. The only changes are in the output stage, so they will sound the same. As for not seeing them back, of course not. Bryston was shipping output modules that the customer would change themselves.
I don't know how you guys could miss seeing those very common problems, they were common enough for me to know there was a problem. The reason they sounded terrible before they got to the bloody hot range is that the bias control circuit was garbage. Poor design and the amp shouldn't have seen the light of day until that was fixed.
When roading these amps, the chassis was too thin, so rack mounted gear would eventually have a tear in the metal along the bottom, front edge. The power switches were not up to the turn on surge (no soft start!), so they would fail for sure at some point unless you left them on 24/7. Without any form of protection network, this was an extremely irresponsible position to take. So the fix for these problems? Bryston told users to leave the equipment on all the time as the amp was designed to "take it". This was of course not true at all, but it ended complaints about power switches and crappy sound during warm-up.
There is only one reason Bryston didn't go out of business. They hid the problems they did have, and the fact that parts will take all kinds of abuse before dying. Cheap parts. If you looked up all these parts they used in the ELectrosonic catalogue, you would see they used a lot of Philips parts (cheap garbage), although the outputs and drivers were Motorola. They had them remarked to "Bryston numbers" to thwart external service people from repairing these. The TO-220 drivers were modified to have longer leads than normal as well.
I have often wondered how good I could make an original 4B sound by using better parts and matching some transistors. I've already looked at the design and know roughly what I want to change. I think I would have a stab at fixing the bias current control circuit as it doesn't have enough authority the way it is now. A soft start circuit and speaker protection would also need to go in. It's already pretty tight in that chassis!
Anyway, the 4B was a low quality amplifier that didn't sound very good compared to other amplifiers in it's power class. It was not reliable compared to other products either. I am extremely happy that they turned that trend around and are now making something they can be proud of.
It blows me away that you didn't recognise the problems with it. I guess you were well insulated from the user market after the sale. My dealings were mostly with companies that bought the product direct. You wouldn't have seen that volume of amplifiers or the use these amplifier were in. One company went back to the BGW 750C amps they had because Bryston product was blowing up, falling apart and cooking all the other gear in the rack. The real 4B is obviously something you are protecting, or you simply didn't see the service side, which Bryston worked hard to keep out of the public view.
One company paid me to reverse engineer the 4B, even with Bryston interfering and objecting to outside involvement. They had had enough of the failures to the point where I was brought in as an objective third party. My diagram matched the one Bryston released a short time later. There are a few details about their claims that you don't know, but I'm not going to drag all that out into the open. Let's just say that some of their advertising claims could not be supported once their facility had been examined ( I was in a tour with a group).
I sure wish you were technical and had an opportunity to work on one. You would have an entirely different opinion compared to what you are saying right now. But if there is one thing I would leave others with it's this. Do not buy an original 4B. It is an incident waiting to happen and should never have been sold.
-Chris
I don't know how you guys could miss seeing those very common problems, they were common enough for me to know there was a problem. The reason they sounded terrible before they got to the bloody hot range is that the bias control circuit was garbage. Poor design and the amp shouldn't have seen the light of day until that was fixed.
When roading these amps, the chassis was too thin, so rack mounted gear would eventually have a tear in the metal along the bottom, front edge. The power switches were not up to the turn on surge (no soft start!), so they would fail for sure at some point unless you left them on 24/7. Without any form of protection network, this was an extremely irresponsible position to take. So the fix for these problems? Bryston told users to leave the equipment on all the time as the amp was designed to "take it". This was of course not true at all, but it ended complaints about power switches and crappy sound during warm-up.
There is only one reason Bryston didn't go out of business. They hid the problems they did have, and the fact that parts will take all kinds of abuse before dying. Cheap parts. If you looked up all these parts they used in the ELectrosonic catalogue, you would see they used a lot of Philips parts (cheap garbage), although the outputs and drivers were Motorola. They had them remarked to "Bryston numbers" to thwart external service people from repairing these. The TO-220 drivers were modified to have longer leads than normal as well.
I have often wondered how good I could make an original 4B sound by using better parts and matching some transistors. I've already looked at the design and know roughly what I want to change. I think I would have a stab at fixing the bias current control circuit as it doesn't have enough authority the way it is now. A soft start circuit and speaker protection would also need to go in. It's already pretty tight in that chassis!
Anyway, the 4B was a low quality amplifier that didn't sound very good compared to other amplifiers in it's power class. It was not reliable compared to other products either. I am extremely happy that they turned that trend around and are now making something they can be proud of.
It blows me away that you didn't recognise the problems with it. I guess you were well insulated from the user market after the sale. My dealings were mostly with companies that bought the product direct. You wouldn't have seen that volume of amplifiers or the use these amplifier were in. One company went back to the BGW 750C amps they had because Bryston product was blowing up, falling apart and cooking all the other gear in the rack. The real 4B is obviously something you are protecting, or you simply didn't see the service side, which Bryston worked hard to keep out of the public view.
One company paid me to reverse engineer the 4B, even with Bryston interfering and objecting to outside involvement. They had had enough of the failures to the point where I was brought in as an objective third party. My diagram matched the one Bryston released a short time later. There are a few details about their claims that you don't know, but I'm not going to drag all that out into the open. Let's just say that some of their advertising claims could not be supported once their facility had been examined ( I was in a tour with a group).
I sure wish you were technical and had an opportunity to work on one. You would have an entirely different opinion compared to what you are saying right now. But if there is one thing I would leave others with it's this. Do not buy an original 4B. It is an incident waiting to happen and should never have been sold.
-Chris
Just in case you missed the product discontinuance notice from TI: 20170721000 PDN.
In July of 2017 Texas Instruments decided to close the fab in Greenock, Scotland. Sadly, this means the LME49710 used in the Modulus-86 has been discontinued. TI will accept orders until August 7th, 2018 and Mouser seems to try to keep the part in stock. Even then, expect this part to drift in and out of stock at Mouser. They are currently out of stock with a delivery date in mid-April. The other distributors (Digikey, Newark, etc.) have been out of stock for a while now.
I bought 120 of the LME49710NA from Mouser while they still had stock and will be selling them with the Modulus-86 boards to those interested for as long as I can maintain stock. I am fully committed to keeping the Modulus-86 going for as long as practically possible (see below for a description of what "practically possible" might look like).
Those of you who are sitting on Modulus-86 (and THAT Driver) boards but haven't gathered parts yet might want to start collecting parts - at least the LME49710NA. Should you not be able to source the IC, contact me via email and I'll help you out. Please do so soon as I will not be able to maintain stock once the IC has been discontinued.
There is no other opamp that is a drop-in replacement for the LME49710 in the Modulus-86. The LME49720 would be the obvious replacement. I can always tie the unused channel off to ground or something. The LME49720 is SMD only now.
So what will the future for the Modulus-86 look like? Good question... I like the Modulus-86 because it provides incredible performance and is an all-leaded build. I would like to keep it going. Here are some of the options for the future:
Based on my experience with the Modulus-286, I'm a bit hesitant to support SMD-only DIY builds. While many complete these builds just fine, quite a few don't, and it's much harder to debug and rework SMD circuits - especially over email - than leaded builds. Thus, if I go with an all-SMD build, I will likely not offer unpopulated boards. Rather, I'll be offering preassembled modules. Needless to say, that comes at a cost. Professional assembly is decidedly not cheap - in particular in low volume. The question is whether folks are willing to pay for the assembly they used to do themselves.
Anyway. Just another speed bump on the road to success for a small business owner...
I have no plans for going away, so I'm sure I'll find a solution.
Tom
In July of 2017 Texas Instruments decided to close the fab in Greenock, Scotland. Sadly, this means the LME49710 used in the Modulus-86 has been discontinued. TI will accept orders until August 7th, 2018 and Mouser seems to try to keep the part in stock. Even then, expect this part to drift in and out of stock at Mouser. They are currently out of stock with a delivery date in mid-April. The other distributors (Digikey, Newark, etc.) have been out of stock for a while now.
I bought 120 of the LME49710NA from Mouser while they still had stock and will be selling them with the Modulus-86 boards to those interested for as long as I can maintain stock. I am fully committed to keeping the Modulus-86 going for as long as practically possible (see below for a description of what "practically possible" might look like).
Those of you who are sitting on Modulus-86 (and THAT Driver) boards but haven't gathered parts yet might want to start collecting parts - at least the LME49710NA. Should you not be able to source the IC, contact me via email and I'll help you out. Please do so soon as I will not be able to maintain stock once the IC has been discontinued.
There is no other opamp that is a drop-in replacement for the LME49710 in the Modulus-86. The LME49720 would be the obvious replacement. I can always tie the unused channel off to ground or something. The LME49720 is SMD only now.
So what will the future for the Modulus-86 look like? Good question... I like the Modulus-86 because it provides incredible performance and is an all-leaded build. I would like to keep it going. Here are some of the options for the future:
- Rev. 2.2: Provide the LME49710 with the boards. That's certainly the easiest stopgap measure.
- Rev. 2.3: Use the LME49720 (SMD only now). Deliver boards with the IC soldered down. Maybe do something with the spare channel.
- Rev. 3.0: Complete redesign using SMD components. Deliver finished modules.
- Let the Modulus-86 sunset with the LME49710. This is my least preferred option.
Based on my experience with the Modulus-286, I'm a bit hesitant to support SMD-only DIY builds. While many complete these builds just fine, quite a few don't, and it's much harder to debug and rework SMD circuits - especially over email - than leaded builds. Thus, if I go with an all-SMD build, I will likely not offer unpopulated boards. Rather, I'll be offering preassembled modules. Needless to say, that comes at a cost. Professional assembly is decidedly not cheap - in particular in low volume. The question is whether folks are willing to pay for the assembly they used to do themselves.
Anyway. Just another speed bump on the road to success for a small business owner...
I have no plans for going away, so I'm sure I'll find a solution.Tom
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I for one would probably not have gone for the MOD-286 and Preamp if they'd only been available pre-assembled. I enjoyed the challenge of the SMD soldering too.
Sucky, but not unexpected. I agree on the SMD. If 90% of clients can do SMD with no issue and 10% have issues, that any profit (and sleep) lost on helping them. Been there done that with other stuff in the past.
Mod -86 with the 49720 pre-soldered on seems to be the pragmatic approach as doesn't alienate the market but minimises your hassle. Otherwise you'll be considering a pick and place machine in your garage
Mod -86 with the 49720 pre-soldered on seems to be the pragmatic approach as doesn't alienate the market but minimises your hassle. Otherwise you'll be considering a pick and place machine in your garage
Oh, DUH! Thank you! I somehow missed that last night when I looked for it on Digikey.
Problem solved ... for now.
Generally, I find leaded parts disappearing fast at the various distributors. Even things like X7R ceramic caps and resistors are disappearing. Granted, there's still a few options to choose from, but there used to be many options to choose from.
I totally get that many build projects for the challenge and fun of it. That's what DIY is about. I'll do my best to support that for as long as possible. But as Bill pointed out, there is a definite tradeoff. There're definitely more support calls on the SMD builds relative to the leaded builds.
Tom
TI also makes a really nice one and sells it at a very reasonable price: TI P/N: DIP-ADAPTOR-EVM. Mouser P/N: 595-DIP-ADAPTER-EVM.
They work well enough - especially if you solder them into the board. I'm not aware of any of them that will take a dual opamp (say LME49720) and adapt it to a single opamp socket (say LME49710) and tie off the unused channel appropriately. Such an adapter could be developed and I did consider that last night as another stopgap measure.
Maintaining inventory of two boards, ICs, and connecting pins would quickly make integrating the LME49720 on the MOD86 board really attractive.
Anyway. It's pretty much a moot point as the LME49720 is available in DIP.
For now, I'll just sell the LME49710 with the MOD86 board. That option is available on my website already.
Tom
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Hi Tom, long time procrastinator. Been sitting on 4 Modulus-86 boards since Aug 2015 when you stopped by my house in Edmonds to demo your friends LXMinis. Still remember that visit well.
It's been a long time away from audio. And now planing to make build a priority. Still going with your amps to drive he Linkwitz LXMinis. And likely add the (2) subs later as well.
Questions I have are:
1. Should I proceed with the 4-Modulus 86 v2.01 boards? Sell them and go with the newer version 2.2 or the Modulus-286?
2. If I go with the boards I have, can I get the LME49710 op-amps from you?
Glad to see you are doing well!
Al
It's been a long time away from audio. And now planing to make build a priority. Still going with your amps to drive he Linkwitz LXMinis. And likely add the (2) subs later as well.
Questions I have are:
1. Should I proceed with the 4-Modulus 86 v2.01 boards? Sell them and go with the newer version 2.2 or the Modulus-286?
2. If I go with the boards I have, can I get the LME49710 op-amps from you?
Glad to see you are doing well!
Al
I remember that visit. Good times! And fantastic timing too. I'm glad you got to hear the MOD86 + LXmini combination.
Rev. 2.0, 2.01, 2.1, and 2.2 are schematically identical. You can see the full revision history in attached image.
I would build what you have. I'll be happy to get you hooked up with LME49710s. Just toss me an email (tomchr@neuro...).
Rev. 2.1 changed to the TO-99 metal can version of the LME49710 as TI discontinued the DIP version for a few months back in early 2016. Then TI had a change of heart and brought back the DIP version after about six months.
Rev. 2.2 changed back to the DIP version as quite a few builders got caught by the little quirk of the TO-99 package: The TO-99 has Pin 8 marked by a tab on the can. All other packages (that I know of anyway) have Pin 1 marked. So quite a few powered up their MOD86 Rev. 2.1 with the LME49710 mounted 45º off. This blows the LME49710. The rest of the circuit is fine and will perform to spec once you replace the LME49710. Rev. 2.2 also had some BOM changes in the DC servo.
The DC servo tweaks in Rev. 2.2 meant getting rid of the expensive foil caps and replacing them with ceramic caps. Rev. 2.1 and 2.2 measure exactly the same, but Rev. 2.2 is about $1 lower BOM cost due to the use of ceramic caps.
Rev. 2.2 is also blue and Neurochrome branded.
Tom
Rev. 2.0, 2.01, 2.1, and 2.2 are schematically identical. You can see the full revision history in attached image.
I would build what you have. I'll be happy to get you hooked up with LME49710s. Just toss me an email (tomchr@neuro...).
Rev. 2.1 changed to the TO-99 metal can version of the LME49710 as TI discontinued the DIP version for a few months back in early 2016. Then TI had a change of heart and brought back the DIP version after about six months.
Rev. 2.2 changed back to the DIP version as quite a few builders got caught by the little quirk of the TO-99 package: The TO-99 has Pin 8 marked by a tab on the can. All other packages (that I know of anyway) have Pin 1 marked. So quite a few powered up their MOD86 Rev. 2.1 with the LME49710 mounted 45º off. This blows the LME49710. The rest of the circuit is fine and will perform to spec once you replace the LME49710. Rev. 2.2 also had some BOM changes in the DC servo.
The DC servo tweaks in Rev. 2.2 meant getting rid of the expensive foil caps and replacing them with ceramic caps. Rev. 2.1 and 2.2 measure exactly the same, but Rev. 2.2 is about $1 lower BOM cost due to the use of ceramic caps.
Rev. 2.2 is also blue and Neurochrome branded.
Tom
Attachments
For the LXmini amp, you'll definitely want the 300 VA transformer (AS-3222).
I put mine in a "BZ4309" chassis from eBay. Now that I've seen ModuShop's products in action, I'd probably go with a 2U Dissipante for future LXmini amp builds. You can get the chassis directly from ModuShop or from the DIY Audio Store (found in the top menu on this forum).
Tom
I put mine in a "BZ4309" chassis from eBay. Now that I've seen ModuShop's products in action, I'd probably go with a 2U Dissipante for future LXmini amp builds. You can get the chassis directly from ModuShop or from the DIY Audio Store (found in the top menu on this forum).
Tom