Bryan Amplifier

[Trevor]

Following on from the Truvox thread and the wonderfull response. I would like to ask if anyone has the circuit diagram for the Bryan 900/9000 model amplifier these were a clone of the Toby Dinsdale amplifier and were contemporary with both the Leak stereo 30 and Truvox TSA 100
The history of these amplifiers is that they were manufactured in Sale Manchester during the 1960,s and early 70,s
I have a no of these in my collection and 1 requires extensive repair
They were held in high regard and priced at a level comparable to the Leak/Truvox etc but I have not been able to obtain any further information
regards Trevor

[Trevor]

I have tonight repairedthe Bryan 9000 amplifier !
what a curiosity
its a normal Tobey Dinsdale all in germanium except that the npn driver transistor is germanium most odd !
however it is correctly biased so i assume it will work oK!
Output devices are RCA 2N2147 high speeed for its time but on 50 volt vce and 2 amps ic max
very fragile
regards trev

[Trevor]

Originally Posted by Trevor

I have tonight repairedthe Bryan 9000 amplifier !
what a curiosity
its a normal Tobey Dinsdale all in germanium except that the npn driver transistor is germanium most odd !
however it is correctly biased so i assume it will work oK!
Output devices are RCA 2N2147 high speeed for its time but on 50 volt vce and 2 amps ic max
very fragile
regards trev

Please note that I meant to say that the NPN driver is a Silicon unit while all the others are Germanium a most unusual arrangement
The amplifier is all modular and very easy to work on I will try to post pictures
regards Trevor

[Trevor]

Please find attached pictures of the Bryan 9000 This shows the modular construction
Extreme left input equalisation
Next tone correction
Next power amplifiers
Heatsink and power transistors
Very easy to service
regards Trev

[D_S_J_R]

I wish I'd looked after my old HiFi Sound magazines from 68 onwards, as this amp was one they liked I think from distant memory.

Keep us posted

[Trevor]

Thanks for your comments re the Bryan
you are the only person I have made contact with that remembers them
My passion is for the transistion between valve and Silicon
this of course includdes Germanium a now neglected area of our audio history
regards Trev

[Trevor]

The Bryan Saga goes on I have retreived from my collection another 9000 amplifier only to find that it is an all Silicon unit fitted with 2N3055 output devices e-line style transistors in place of the OC71 etc
again its all modular contruction and appears to be a modified circuit in that it has a modified Toby Dinsdale input stage
The unusual thing with the Bryan is that the input phone stage has a buffer amplifier before the equalisation stage

I wish I couls contact any ex Bryan worker so that I can further my research
Regards Trev

[Mignun67]

Trev, thanks for the interesting posts on the Bryan 9000. I have one of these and it's in really lovely condition. I haven't used it for a while - indeed, I need to make up some more cables with spades as all I have right now are 4mm banana'd leads - but if I recall it was rather nice. Mine has the 2N3055 output devices.

I've never seen another one, or read anything about Bryan until I saw your thread. Anyway, you have inspired me to get it out of its box and back into action again.

[Mignun67]

Trev, I notice that the knobs on your exmple are different to the ones on mine, which are slightly larger and solid aluminium with a groove for indication of level etc...

I dug out an old copy of The Record Review and found a mention of the Bryan 9000. It was in their recommended systems section and they rated it as A+. To put that into some perspective, only the Quad, Sugen and Radford pre/powers attained this rating. A sugden A21 achieved only a B...

[Trevor]

Thank you for your comments re the Bryan
I wish I could find out more re this important era in amplifier design!
Did you purchase your new if so from where?
As to the Knobs Bryan were very small scale production and I feel sure that they were subject to ongoing improvement ,the knobs on my Bryans are all the same maybe a lower cost option in my case
I will shortly attempt to get the schematic on line
regards Trev
best regards trev

[Mignun67]

One other interesting snippet I picked up thanks to Record Review was that the 9000 was supposedly available as either an 8-16ohm or 4-8ohm version. There was also talk of a forthcoming 8000 model with more power. And then the trail goes cold and I see no more mention of Bryan. I did see one or two dealers listing stocking Bryan around 1971 but then nothing.

I got this example second-hand although from the first owner and I think the knobs were as supplied. Mine comes in a wooden case, although I don't know whether this was standard or not. When I can find my camera I'll post a picture. The blue lamp was way ahead of its time...

[Trevor]

I have a rare 8000 model with its regulated supply
I think its a basic 9000 with the improved supply as mentioned
I have yet to examine it in detail but will post as and when things come to light
best regards trevor

[Trevor]

I have at last worked out the schematic for the Bryan Silicon amplifier will post a diagram and comments later on!
Its a strange 1
Regards Trev

[Trevor]

At first glance the power amplifier looks very similar to the Leak stereo thirty!
However on close examination you will find their is no dc feed back to the emitter of the first transistor,and the amplifier is left hanging on to the first transistor
Ac feedback is via the 3.9 k resistor via a small value electrolytic capacitor
The bias arrangement is also most unusual in that it is derived from a 2.7 volt and parallel connected 5k pot the drive for the pnp driver being taken from the slider of the pot
The base emitter resistors on the output transistors "2N3055" are the highest I have ever seen at 1k
The output capacitor has no feed back and is left to its own devices
all in all a unusual arrangement however it does sound nice
I hope that you can see the drawing as I am still having problems with the scanner
Best regards Trevor

[Mignun67]

Trevor, interesting info, thanks.

Anyway, here's a picture of my Bryan 9000 showing the knobs....

[Trevor]

What a cracking example it a lovely amplifier!
What is the serial no on the back ?
You will have to get it going!!!
Regards Trev

[Mignun67]

Oh, it's going just great! Serial number is 91143. Somehow I can't imagine they built that many!

[Mignun67]

Hooked it all up properly this afternoon and it's all working well. Very little noise on the pots (even better after running them up and down a bit) and only a tiny bit of background noise when you put your ear close by the speakers (probably needs a re-cap), but otherwise sounding great with a surprisingly dynamic performance and excellent sense of space. In fact, I'd rate it way ahead of a Rotel RA-820B and marginally ahead of an A&R A60 I have here, but not quite up to my Naim Nait 2 that has just come back from a full service. Impressive. I like this amp.

[Trevor]

Not bad for a Manchester company in 1970
The design on these is quite unusual The Phono stage is in some ways unique
They did not make many of these !
I wish some-one any one could come up with some information on these rare items
regards Trev

[MrElectronicman]

Having seen the pictures, I remember this amp now, unfortunately I cannot help on this one.

Nice amp, well made, a bit like the Truvox TSA 100 with the modular construction, on the other hand I always thought the Leak Stereo 30 looked a bit cheap on the inside.

When I first got interested in transistor amps I started to make a design that came out in Wireless World, even made the PCB's, all drawn by hand, but when I found out the cost for the mains transformer and other parts I had second thoughts.

The nail in the coffin so to speak, was the construction of the case which was beyond my resources at the time, so I broke down and bought a ready made amp.

If I remember rightly I had heard about the Bryan Amp, but none of the shops in my area knew anything about it.

Interesting about the use of Germanium and Silicon. I remember that Truvox 100 series of Tape Recorders first came out using germanium transistors, and I have a hand written note in the service manual indicating that in a later version they used all silicon, the inference being that this was a direct substitution. Since this was just for the preamp, I am guessing that biasing was not a major concern.