Looking for info on what I need to change component wise, what components I can leave out to make a single channel SSE.
For the power supply transformer, can I halve the current ratings on each of the windings (700 to 750 VCT @ 175 mA DC output --> 88 mA, 5 VAC at at least 2 amps --> 1A or for 5R4 rectifier 3 amps --> 1.5A, The main filament winding should be 6.3 VAC at at least 5 amps --> 2.5A)?
At the moment I would plan to use a Sovtek 5AR4 rectifier, 12AT7 preamp tube, Sovtek 6550WE output tube, and for the output transformer an Edcor XSE15-8-5k.
For the power supply transformer, can I halve the current ratings on each of the windings (700 to 750 VCT @ 175 mA DC output --> 88 mA, 5 VAC at at least 2 amps --> 1A or for 5R4 rectifier 3 amps --> 1.5A, The main filament winding should be 6.3 VAC at at least 5 amps --> 2.5A)?
At the moment I would plan to use a Sovtek 5AR4 rectifier, 12AT7 preamp tube, Sovtek 6550WE output tube, and for the output transformer an Edcor XSE15-8-5k.
You cannot halve the rectifier current winding. A 5AR4 needs 2 amps, no matter what. 3 for the 5R4.
You'll still need to heat both halves of the 12AT7 (0.3 amps) & a single output tube (1.6 amps) That means at least 2 amps on the 6.3V winding, bare minimum. 3 is better.
That gives you some overhead & will allow it to run cooler.
90-100 on the B+ winding should be ok.
Something akin to a Hammond 273DX or a 274AX is roughly correct. With the former you would be limited to a 5AR4 or 5V4G rectifier.
You'll still need to heat both halves of the 12AT7 (0.3 amps) & a single output tube (1.6 amps) That means at least 2 amps on the 6.3V winding, bare minimum. 3 is better.
That gives you some overhead & will allow it to run cooler.
90-100 on the B+ winding should be ok.
Something akin to a Hammond 273DX or a 274AX is roughly correct. With the former you would be limited to a 5AR4 or 5V4G rectifier.
Appreciate the advice on the transformer and pointing out the 6ab4. I will plan to use that preamp tube.
Should I follow George's SE advice in this post?
https://www.diyaudio.com/community/threads/tubelab-se-monoblock.119065/
Should I follow George's SE advice in this post?
https://www.diyaudio.com/community/threads/tubelab-se-monoblock.119065/
It is not clear if you are building the monoblocks using a PCB or point to point wiring.
The 6AB4 is indeed half of a 12AT7, but it is a 7 pin tube so it requires a 7 pin miniature socket which will not fit in the PCB. It will work fine in a point to point build if you can find the socket for it.
I made a pair of monoblock SSE's about 15 years ago using the PCB by building them with all the typical parts and running both channels in parallel for twice the power output. You would then use an OPT that's half the impedance that you would have used for a stereo amp.
It is also possible to make a push pull SSE by running the two channels out of phase with an interstage transformer with a CT and a push pull OPT for about 40 watts of power.
The 6AB4 is indeed half of a 12AT7, but it is a 7 pin tube so it requires a 7 pin miniature socket which will not fit in the PCB. It will work fine in a point to point build if you can find the socket for it.
I made a pair of monoblock SSE's about 15 years ago using the PCB by building them with all the typical parts and running both channels in parallel for twice the power output. You would then use an OPT that's half the impedance that you would have used for a stereo amp.
It is also possible to make a push pull SSE by running the two channels out of phase with an interstage transformer with a CT and a push pull OPT for about 40 watts of power.
George,
I am wanting to build the mono SSE using one of your PCBs. The mono amp would be used in an old mono radio cabinet, so I only need one channel. Glad you pointed out that the 7 pin socket will not fit, if I go that route I might have to see if I can make an adapter.
The parallel option sounds good, so I just build it normally and get an output transformer that has an impedance of 2.5k Ohms instead of 5k Ohms? Like the Edcor XSE25-2.5k.
I am wanting to build the mono SSE using one of your PCBs. The mono amp would be used in an old mono radio cabinet, so I only need one channel. Glad you pointed out that the 7 pin socket will not fit, if I go that route I might have to see if I can make an adapter.
The parallel option sounds good, so I just build it normally and get an output transformer that has an impedance of 2.5k Ohms instead of 5k Ohms? Like the Edcor XSE25-2.5k.