Hi Tony,
Have you tried e-mailing Quad, they are well known for their excellent after sales back-up.
From experience I would be very wary about subbing a transistor in a Quad amp if you want it to sound the same as they intended.
I'm sure they'll send you the correct part via a credit card order, even if you are not in the trade.
Is that driver the only faulty part though ?
Cheers ........ Graham.
Have you tried e-mailing Quad, they are well known for their excellent after sales back-up.
From experience I would be very wary about subbing a transistor in a Quad amp if you want it to sound the same as they intended.
I'm sure they'll send you the correct part via a credit card order, even if you are not in the trade.
Is that driver the only faulty part though ?
Cheers ........ Graham.
What are the chances! I've had no problems in the past. If you call them they can probably refer you to someone internally.
My towers transistor selector is 150 miles away at the moment so I can't help you with a replacement, if you are replaceing tr105 I would look at replacing tr106 also with a compliment to your chosen transistor .. if your other channel is still ok it should be easy to check the suitability of the replacement.
Please do look at this site though it seems they might know what they're talking about -
http://www.geocities.com/ResearchTriangle/Lab/6722/quadequitran.html
Both the BC441 and BC461 are available from
www.farnell.com (click the aussie flag edit:sorry kiwi flag
)
Best of luck,
Paddy
My towers transistor selector is 150 miles away at the moment so I can't help you with a replacement, if you are replaceing tr105 I would look at replacing tr106 also with a compliment to your chosen transistor .. if your other channel is still ok it should be easy to check the suitability of the replacement.
Please do look at this site though it seems they might know what they're talking about -
http://www.geocities.com/ResearchTriangle/Lab/6722/quadequitran.html
Both the BC441 and BC461 are available from
www.farnell.com (click the aussie flag edit:sorry kiwi flag
)Best of luck,
Paddy
Quad 303 transistors
I finally have a reply from the Service Manager who had been on leave . He gave me the price for a replacement, with some comments about credit card usage. I replied saying I had been seeking info about a current replacement.
He has now replied saying that all they do is supply.
I rather think service standards have slipped ....
Cheers Tony
I finally have a reply from the Service Manager who had been on leave . He gave me the price for a replacement, with some comments about credit card usage. I replied saying I had been seeking info about a current replacement.
He has now replied saying that all they do is supply.
I rather think service standards have slipped ....
Cheers Tony
oh dear
That's a pity, they were so helpful in the past. The again he is a manager, most managers I've worked under didn't know their **** from their elbow when it came to things technical.
How much are they charging? Are they supplying the original transistor or an equivalent?
Good Luck,
Paddy
That's a pity, they were so helpful in the past. The again he is a manager, most managers I've worked under didn't know their **** from their elbow when it came to things technical.
How much are they charging? Are they supplying the original transistor or an equivalent?
Good Luck,
Paddy
TonyF
I would buy them. Sounds like excellent service to me.
Quad stocked RCA, and the characteristics matched their design for stability and sound etc.
There were two versions of your amplifier - relating to slightly different bias setting arrangements. Serial no. is relevent for that.
You would probably pay near that for quality substitutes anyway, and you still won't be sure they match.
Cheers ........... Graham.
I would buy them. Sounds like excellent service to me.
Quad stocked RCA, and the characteristics matched their design for stability and sound etc.
There were two versions of your amplifier - relating to slightly different bias setting arrangements. Serial no. is relevent for that.
You would probably pay near that for quality substitutes anyway, and you still won't be sure they match.
Cheers ........... Graham.
Quad 303 transistors
I did get a reply. The Service Manager says " supporting old Quad products often means customers do not purchase new. Therefore, we sell and supply replacement parts but do
not offer a service for people to purchase parts elsewhere"
Ah well.......
But I found that the NZ Branch of RS Components had BC143 in stock. Ordered packet of 5 online, which was delivered next morning. Now to find out if this was the only fault.
Cheers
Tony
I did get a reply. The Service Manager says " supporting old Quad products often means customers do not purchase new. Therefore, we sell and supply replacement parts but do
not offer a service for people to purchase parts elsewhere"
Ah well.......
But I found that the NZ Branch of RS Components had BC143 in stock. Ordered packet of 5 online, which was delivered next morning. Now to find out if this was the only fault.
Cheers
Tony
I note you have found transistors
I can recommend BD140 Pnp Tr105 ,and Bd 139 Tr106
This combination is used in a large number of amps
to drive the ubiquitous 2N3055. The only change is
the pinout for these transistors is different and you
need to back the bias off a bit ( can still be set to
Quads specification).
If you have a failed upper triplet transistor it is likely
one of the others is out too. Let me know if you
need further help
If you have a failed regulator transistor a MJ15003
works well. cheers / Chris
I can recommend BD140 Pnp Tr105 ,and Bd 139 Tr106
This combination is used in a large number of amps
to drive the ubiquitous 2N3055. The only change is
the pinout for these transistors is different and you
need to back the bias off a bit ( can still be set to
Quads specification).
If you have a failed upper triplet transistor it is likely
one of the others is out too. Let me know if you
need further help
If you have a failed regulator transistor a MJ15003
works well. cheers / Chris
Hi Tony,
There is another option.
You could enquire about the price of a complete pcb.
Quad are very competitive in this regard, then all you would need to check are the outputs. You might get the whole pcb for £20 and then you'd have spares from the the old board.
I'd be very wary of changing to an alternative device within half of a complementary output stage.
Cheers ......... Graham.
There is another option.
You could enquire about the price of a complete pcb.
Quad are very competitive in this regard, then all you would need to check are the outputs. You might get the whole pcb for £20 and then you'd have spares from the the old board.
I'd be very wary of changing to an alternative device within half of a complementary output stage.
Cheers ......... Graham.
Graham
I agree with comments concerning upper
triple and lower triple having different transistors
thats why I recommended not only TR105 as a BD140
but also TR106 as a BD 139
I am currently using these transistors in a Quad 303
and made recommendations because I know they work
well, albiet with pinout differences, and bias adjustment
which is adjustable to Quads specification. These
transistors have been used in literally thousands of
amps to drive 2n3055's , ie the famous ETI480
- however not necessarily in the same configuration
Quad use. I agree ideally transistors should be replaced
identically but 38496 and 38495 are not readily available.
and substitutes if they work well can be recommended
particularly as this amp has been out of production for
nearly 25 years.
I may take Quad up on some spare boards too
thanks for that
Cheers / Chris
I agree with comments concerning upper
triple and lower triple having different transistors
thats why I recommended not only TR105 as a BD140
but also TR106 as a BD 139
I am currently using these transistors in a Quad 303
and made recommendations because I know they work
well, albiet with pinout differences, and bias adjustment
which is adjustable to Quads specification. These
transistors have been used in literally thousands of
amps to drive 2n3055's , ie the famous ETI480
- however not necessarily in the same configuration
Quad use. I agree ideally transistors should be replaced
identically but 38496 and 38495 are not readily available.
and substitutes if they work well can be recommended
particularly as this amp has been out of production for
nearly 25 years.
I may take Quad up on some spare boards too
thanks for that
Cheers / Chris
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