[rnros]

If I hadn't listen to these tubes before I wouldn't dare plunge in but I have quite extensively. In an amp not design to run it but it sounded good. I've never tried EL12 spez but I've tried EL11, EL12, EL12n both as driver and power tubes. They sound dynamic, clear, bold and energetic. It's like EL3N with the heavens open.

Now I'll have to try those. At least the EL11s. Project sounds exciting. And more every day.

Good idea to keep the tube rectifier. Definitely helps to shape the SQ. May be all you will ever want or need with those tubes.
Some good and inexpensive rectifiers available for experimentation. Previously recommended by Glenn on this thread.
Even if they never become a favorite, the experimentation is interesting. Less than $20.
Case in point, 5AW4 cleans up the little bit of extra bass diffusion I hear with the 6BL7s, makes them as good as the 6BX7s to my ear.
Another is the 5CU4, but that may not have the PIV you need. I think the 5AW4 is OK.
RK60 has rich low end, not excessive, only $40, may be nice with the Telefunken.

 

[UntilThen]

I was thinking RCA 5U4G. I'll have Gibosi suggest some more cheap rectifiers for me, that is suitable for this amp.

 

[UntilThen]

Glenn I think I will need a durable Yamamoto socket for the rectifier.

 

[rnros]

I was thinking RCA 5U4G. I'll have Gibosi suggest some more cheap rectifiers for me, that is suitable for this amp.

Glenn I think I will need a durable Yamamoto socket for the rectifier.

Two very good ideas.

 

[2359glenn]

Glenn I think I will need a durable Yamamoto socket for the rectifier.

I agree they are a little pricey but may be worth it in the long run.
About $55 each plus shipping from Germany.

 

[UntilThen]

I agree they are a little pricey but may be worth it in the long run.
About $55 each plus shipping from Germany.

Becaue knowing UntilThen there WILL be rectifiers rolling until THEEND comes along.

 

[2359glenn]

Now I'll have to try those. At least the EL11s. Project sounds exciting. And more every day.

Good idea to keep the tube rectifier. Definitely helps to shape the SQ. May be all you will ever want or need with those tubes.
Some good and inexpensive rectifiers available for experimentation. Previously recommended by Glenn on this thread.
Even if they never become a favorite, the experimentation is interesting. Less than $20.
Case in point, 5AW4 cleans up the little bit of extra bass diffusion I hear with the 6BL7s, makes them as good as the 6BX7s to my ear.
Another is the 5CU4, but that may not have the PIV you need. I think the 5AW4 is OK.
RK60 has rich low end, not excessive, only $40, may be nice with the Telefunken.

May be a alternative to ridiculously expensive 300Bs.
And have better longevity.
I am excited about this project too.

 

[2359glenn]

Becaue knowing UntilThen there WILL be rectifiers rolling until THEEND comes along.

How true
Glad to see you stopped tube rolling on the OTL. And you are staying with the cheep 6BX7s not the over priced GEC6AS7s
I made this amp to use cheep tubes but everyone goes for the GEC and it don't sound better. Maybe better then other 6AS7s
in amps that there are no choice.

 

[UntilThen]

I

May be a alternative to ridiculously expensive 300Bs.
And have better longevity.
I am excited about this project too.

I feel safer when the designer is excited about the project.

 

[UntilThen]

Well I might be selling off my priceless power tube collection. GEC 6AS7G etc etc.

 

[gibosi]

No 3DG4 voltage to high for it. Tube should have a PRV rating of at least 850 volts or higher that means no GZ32 it will blow up.
I already had someone try to use a GZ32 in a 300B amp and it blew up and blew the fuse in the amp.

As I read this RCA datasheet for the 3DG4, it has a PIV / PRV of 1050. Since this value exceeds 850, I would think that the 3DG4 is OK for the EL amp? Or am I missing something?

http://www.tubebooks.org/tubedata/HB-3/Receiving_Tubes_Part_1/3DG4.PDF

 

[2359glenn]

As I read this RCA datasheet for the 3DG4, it has a PIV / PRV of 1050. Since this value exceeds 850, I would think that the 3DG4 is OK for the EL amp? Or am I missing something?

http://www.tubebooks.org/tubedata/HB-3/Receiving_Tubes_Part_1/3DG4.PDF

Look under typical operation 550 volts plate to plate that is 275 volts per plate. And DC output voltage 300 volts.
It probably would work but risky.
It looks like a GZ32 will work too but don't try it. Somebody done that in a 300B amp and it blew up. It can work at 500 volts at reduced current
125 ma max at this voltage.

 

[gibosi]

Look under typical operation 550 volts plate to plate that is 275 volts per plate. And DC output voltage 300 volts.
It probably would work but risky.
It looks like a GZ32 will work too but don't try it. Somebody done that in a 300B amp and it blew up. It can work at 500 volts at reduced current
125 ma max at this voltage.

I think I understand... Having a PRV above 850 volts is not in itself sufficient. It is also necessary to look at AC Plate to Plate and DC Output voltage at full load to consider how it might perform at 425 volts.

Considering all these characteristics, electrically, the 5R4GY is much better:

http://www.tubebooks.org/tubedata/HB-3/Receiving-Type_Industrial_Tubes/5R4GY.PDF

PRV = 2800 (below 20,000 feet)

AC Plate to Plate value = 1800 volts
DC Output voltage at full load = 950 volts

I was thinking RCA 5U4G. I'll have Gibosi suggest some more cheap rectifiers for me, that is suitable for this amp.

As my experience is with the GOTL, about 250 volts with two 6AS7G and 325 volts with four 6BX7, I just don't know which cheap rectifiers can handle 425 volts. For now, it is best to let Glenn guide you.

 

[UntilThen]

Thanks gibosi you are a great guide that is for sure.

But I will let master Yoda guide me.

In other news, I will get a chance to have the EC Studio for one week in July to listen. I am looking forward to it. Before I call this hobby TheEnd, I want to listen to all the top tube amps and I believe the EC Studio is pretty much close to the end....

Unless someone lends me a Glenn's 300b amp.

I won't be getting a Glenn 300b or an EC Studio amp. For my fairy tale ending it will be the EL11 / EL12 Spez amp. For better or for worst, like they say.

 

[UntilThen]

I will just call the EL11 and EL12 spez amp as

'Spez'.