Ahh yes I see. So do it after that cap ;-) . But I see Mooly already fixed it.
Jan
output transformer perhaps?
If I may add to this, the power supply capacitor too is part of the sound. Both are Eurocap 10mF electrolytics. Although they look like decent quality, bulky caps, looks can be deceiving sometimes. I've never heard of Eurocap nor can I find any traces of this brand on the internet (except the odd surplus or online auctions site).
I was thinking of replacing the original A51 circuit's electrolytics with film capacitors. I procured quite a few from an auction site (without any guarantees as to their actual provenance of course, although the sport a well known brand name). I got a few boxes of them posted to me. I reckon I got about half the capacitance used in the whole circuit. Mind you, the original A51 circuit calls for 2.5mF electrolytics (about two and a half of those for a single power supply, make that three of those for a dual power supply conversion). I looked online for surplus/used industrial film capacitors. It'll cost a few hundred pounds (in addition to what I've already spent) to get the additional capacitance required (including the 4mF bypass caps used in the lower power transistor). All the capacitors put together will make for a nice pedestal on which to stand the rest of the amp's circuits (not to mention a huge jumble of wiring of unknown inductance to connect them together).
I keep toying with the idea inside my mind - such is the nature of human folly.
Rather than go this admittedly expensive and labour intensive route - whose outcome can only be described as uncertain - I was thinking of substituting the output cap with an output transformer. This is a better solution, given that in the updated circuit of the A21 the large caps have been upgraded to four times the original size.
In particular, I was thinking of a double C core transformer made by ampliatubes.fr (Transfo de sortie pour amplificateur a transistors - TSM "ampliatubes.fr"). The specs look nice and they claim that class A, single ended (?) version is possible. Price not too bad (cerainly less than twenty kilos of capacitors' worth).
What do people think of a conversion of this circuit to a transformer output?
Can anyone provide precise transformer specifications for this circuit?
I reckon, conversion, with postage costs for postage within Europe will be a few hundred pounds per channel.
Regards
Stelios
If I may add to this, the power supply capacitor too is part of the sound. Both are Eurocap 10mF electrolytics. Although they look like decent quality, bulky caps, looks can be deceiving sometimes. I've never heard of Eurocap nor can I find any traces of this brand on the internet (except the odd surplus or online auctions site).
I was thinking of replacing the original A51 circuit's electrolytics with film capacitors. I procured quite a few from an auction site (without any guarantees as to their actual provenance of course, although the sport a well known brand name). I got a few boxes of them posted to me. I reckon I got about half the capacitance used in the whole circuit. Mind you, the original A51 circuit calls for 2.5mF electrolytics (about two and a half of those for a single power supply, make that three of those for a dual power supply conversion). I looked online for surplus/used industrial film capacitors. It'll cost a few hundred pounds (in addition to what I've already spent) to get the additional capacitance required (including the 4mF bypass caps used in the lower power transistor). All the capacitors put together will make for a nice pedestal on which to stand the rest of the amp's circuits (not to mention a huge jumble of wiring of unknown inductance to connect them together).
I keep toying with the idea inside my mind - such is the nature of human folly.
Rather than go this admittedly expensive and labour intensive route - whose outcome can only be described as uncertain - I was thinking of substituting the output cap with an output transformer. This is a better solution, given that in the updated circuit of the A21 the large caps have been upgraded to four times the original size.
In particular, I was thinking of a double C core transformer made by ampliatubes.fr (Transfo de sortie pour amplificateur a transistors - TSM "ampliatubes.fr"). The specs look nice and they claim that class A, single ended (?) version is possible. Price not too bad (cerainly less than twenty kilos of capacitors' worth).
What do people think of a conversion of this circuit to a transformer output?
Can anyone provide precise transformer specifications for this circuit?
I reckon, conversion, with postage costs for postage within Europe will be a few hundred pounds per channel.
Regards
Stelios