SSE - Semiconductors are optional?

[txtone]

I would like to clarify something about the semiconductors for the SSE build. I have read that the semiconductors are not necessary if a rectifier tube will be used, such as an 5AR4 or GZ-34 tube. Is that true? If so, does that mean the chapter regarding semiconductors (from the assembly manual) can be skipped, and parts D1, D2, U10, and U20 can be left off the board entirely?

Next question. If a rectifier tube WILL be used is it ok to install the semiconductors? Or will that cause problems?

Thanks in advance!

 

[cogitech]

U10 and U20 are CCS (constant current sources) and they need to be installed no matter what.

The diodes D1 and D2 can be omitted if you want to use tube rectification exclusively.

If you want the option of switching between solid state rectification and tube rectification, then install the diodes D1/D2 and wire up the switch during the build.

Please note: newer boards include D3, D4, and TR1. All of them are highly recommended. They can be jumpered if you feel reckless.

SSE - D3, D4 and TR1

Starting a SSE build

 

[txtone]

U10 and U20 are CCS (constant current sources) and they need to be installed no matter what.

The diodes D1 and D2 can be omitted if you want to use tube rectification exclusively.

If you want the option of switching between solid state rectification and tube rectification, then install the diodes D1/D2 and wire up the switch during the build.

Please note: newer boards include D3, D4, and TR1. All of them are highly recommended. They can be jumpered if you feel reckless.

Thanks! Should D1 and D2 be the FRED 1200V TO-220 type? Or is it recommended to put 1N4007s in all four?

Also, is this part suitable for TR1? Amphenol Advanced Sensors - CL-140 - Thermistor,ICL,NTC,Res 50 Ohms,Tol 25%,Radial,Disc,Cur-Rtg 1.1 A,Dia-Max 0.45 In - Allied Electronics & Automation

 

[cogitech]

D1 and D2 should be FRED

D3 and D4 should be 1N4007

That CL-140 will work fine.

 

[txtone]

D1 and D2 should be FRED

D3 and D4 should be 1N4007

That CL-140 will work fine.

I looked at the board (after I responded) and this makes perfect sense.

Thanks again!

 

[boywonder]

If you go the switch route...only flip the switch with the amp powered down....and keep in mind SS rectification will likely result in a little higher B+ voltage....the forward voltage drop of the FREDs is less than a 5AR4/5U4 etc.