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Bijou All Tube Futterman Headphone Amplifier - Page 283

post #4231 of 4234
Quote:
Originally Posted by bhjazz View Post
 

 

That's good to know, then.  I still need to get a hold of Jeff Rossel and see what tubes I actually have.  The wiring differences are my final concern for this issue.  I'm wishing there were an easier way to tell (which tubes I actually have). 

 

Yes, I have an EZ81, as well as the 370DAX, so I should be good to go for a power supply.  

 

You should be fine on the power supply front. 

 

The ECC99 is a modern tube from JJ. It would have a big red JJ logo on it. It's based on the 6n6p, but has higher plate resistance. 

 

If there's no JJ logo, it's probably 6n6p-i or 6n6p-ev, and the only difference there is the heater current iirc. My heater supply is doing just fine with a pair of 6n6p-i at almost an amp each and a pair of 6n1p at 600ma each along with the EZ81. 

 

6h30-pi was a premium option and i doubt glassjar ever sold any. You would have noticed at $30/tube. 

 

Your preamp tubes should be clearly marked too, but i don't recall any wiring differences between 6dj8, 6922, 6n1p, or 6n23p -- the 6n23p being the real 6922 clone from russia. CEI even sold them labeled as 6DJ8. The 6n1p just has slightly lower gm and a much hotter filament. 

post #4232 of 4234

Thanks for all the help, Eric. I do appreciate it!

 

First, the input tubes are JAN Philips 6922.  I have another pair of EH 6922s (matched), and another matched pair of JAN Philips 6DJ8.  

 

AND - I just heard back from Jeff Rossel.  Looks like the variant I have is what I suspected: Russian 6N6P.  They are marked with partial Cyrillic characters, and one is labeled CCCP.  Gotta love that.  From what I have read, these do not really need to be a matched pair.  

 

Anyway, now I know for sure that the wiring will be using pins 4, 5 and 9 for the heater arrangement. This also means I can use the ECC99 tube as well.  Cool!  I'll have to get a pair of ECC99 for fun.

 

The rectifier tube I have, is definitely a JJ - red logo and all.  

post #4233 of 4234

Edit: Just noticed my Glass Jar kit includes R6 and R9 at 332k, instead of the specified at 348k.  Does this lower resistance help address the issues with using 6N6P tubes and it's affect on the B+ (as noted in this thread)?

 

Thanks!

 

Another Edit:  I am assuming it is related to this:

 

Quote:
Originally Posted by ericj View Post
 

When i was digging around six months or so back i found resistor values to increase the plate current on 6n6p tubes. And 6n1p - which is the combo i am using. I don't think i implemented it yet, and i am not sure where i found those values, but I will look again because i am revamping my beloved old ToasterAmp(tm) Bijou lately. 


Edited by bhjazz - 3/7/17 at 9:09pm
post #4234 of 4234

The Mundorf Silver In Oil caps arrived today for C3 and C4 on the amplifier boards.  Also, a pair of Mundorf MLytic AG caps for the output on my Ventus, which I hope to rebuild once the Bijou is done.  

 

Per my previous message I sent a quick email to Jeff, and he confirmed that he does, in fact, have different values than the original BOM.  So the slight change is expected.  I also noticed that he sent 450V 680uF caps for the power supply, too.  Excellent.

 

Things are coming together.  

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