A softer rectifier...

[dehughes]

Hello again,

I have GZ34s, I have 5V4s, I have 5Y3s.....now is there a rectifier that sits somewhere between a 5Y3 and a 5V4, that is interchangeable with these types? That is, I don't want to push my tranny's heater winding any harder that these tubes would already (trying to keep things around 2.0 amps...), so no 5U4s, etc...

Would a 5R4 work out? The amp in question is an AC30-ish creation with MM trannies....plus, I'd like to have some lower output recto options around anyway.

Thanks!

[JimiB]

5R4 is a GZ34

[philmanatee]

The 5R4 will drop a lot more voltage than the 5AR4 and uses 2.0 amps. Phil

[dehughes]

The 5R4 is a different tube entirely from the GZ34 (5AR4), if my information is correct.

So would a 5R4 be in between a 5AR4 and a 5Y3 in terms of voltage drop/sag/softness, etc.? Would a 5R4 be a drop-in replacement with these other types, or would I have to re-wire the recto socket?

Thanks!


david

[philmanatee]

As far as I know the pin out is the same, I've never used one so I couldn't say where it falls between a 5AR4 an a 5Y3. They are much cheaper than 5AR4's though for NOS tubes. Phil

[philmanatee]

Check out this link
http://nj7p.org/Tube4.php?tube=5R4GYA

[dehughes]

Nice. So, according to this data, a 5R4 is acually a softer tube than a 5Y3, correct?

[philmanatee]

I keep hoping that someone that has tried a 5R4 will respond to this. If I have time tomorrow I'll throw one in my AC-30 and report back, having time is the key. Phil

[Rattlecat]

One of the things also to keep an eye on is the max input capacitance for the rectifier tube... e.g. if you have a capacitor can right after the rectifier, there are limits on how big it can be. I am not an expert on the subject, but know enough to be leary about this. The 5r4gya seems very low at 4uf, but this is also at 750 volts ( typical opertation ). I'm not sure how much room there is to play with if you use less voltage. Maybe someone here can shed some light on this.

[dehughes]

One of the things also to keep an eye on is the max input capacitance for the rectifier tube... e.g. if you have a capacitor can right after the rectifier, there are limits on how big it can be. I am not an expert on the subject, but know enough to be leary about this. The 5r4gya seems very low at 4uf, but this is also at 750 volts ( typical opertation ). I'm not sure how much room there is to play with if you use less voltage. Maybe someone here can shed some light on this.

I was told that the 5R4GA can handle an initial electrolytic capacitor that is 20uf or LESS, so you'd not be albe to use this recto in a DC30, King Royale, or any other amp that runs about 33uf right off the bat. This is fine, as I'm running a 16uf cap as my first one off the recto, so a 5R4 should be just fine.