Hi,
After lots of searching I have decided to build a 2a3 se amp based on 6SL7 driving 2a3 Loftin White topology.
With the elevated bias required to ommit the coupling capacitor I need 400v or so of HT.
What rectifier would anyone recommend, exluding GZ 37 (based on price)
to power two channels, and what secondary voltage should I be looking for for the mains transformer.
I was thinking of 350-0-350 secondary, GZ34/5AR4 and adjusting the input cap before the 10mH choke to attain the correct HT.
I don't know why all the circuits I have seen appear to have GZ37's when the GZ34 appears to have the voltage and current rating required.
The only thing I can think of is the voltage drop over the rectifier.
Can anyone clarify this for me?
Any help would be appreciated.
Bob
After lots of searching I have decided to build a 2a3 se amp based on 6SL7 driving 2a3 Loftin White topology.
With the elevated bias required to ommit the coupling capacitor I need 400v or so of HT.
What rectifier would anyone recommend, exluding GZ 37 (based on price)
to power two channels, and what secondary voltage should I be looking for for the mains transformer.
I was thinking of 350-0-350 secondary, GZ34/5AR4 and adjusting the input cap before the 10mH choke to attain the correct HT.
I don't know why all the circuits I have seen appear to have GZ37's when the GZ34 appears to have the voltage and current rating required.
The only thing I can think of is the voltage drop over the rectifier.
Can anyone clarify this for me?
Any help would be appreciated.
Bob
37 vs 34
The GZ37 has a reputation for being tougher than the GZ34. That reputation comes with a demand for an extra amp of filament current.
The GZ37 has a reputation for being tougher than the GZ34. That reputation comes with a demand for an extra amp of filament current.
So other than the filament current rating , is there anything that should prevent me from using a GZ34 or equivalent from performing the job?
The circuit am going to build should be something like the one shown here... www.netaxs.com/~vkalia/diypix/dc2a3-schema.jpg
The circuit am going to build should be something like the one shown here... www.netaxs.com/~vkalia/diypix/dc2a3-schema.jpg
I use a GZ32 for my 6B4G stereo amp. (6B4G is a 6 volt 2A3)
They are great, even with a 400V B+. A GZ34 will be fine, especially if you can get an old mullard (they last for ever!)
Also I would suggest trying a few different driver stages with the 6SL7. You might try the Angela.com 2001 edition its pretty decent sounding imho.
Also you need a 10H choke, not 10mH!
They are great, even with a 400V B+. A GZ34 will be fine, especially if you can get an old mullard (they last for ever!)
Also I would suggest trying a few different driver stages with the 6SL7. You might try the Angela.com 2001 edition its pretty decent sounding imho.
Also you need a 10H choke, not 10mH!
Oops... mH is force of habit from x over designs!
Thanks for that info.
I was initially going to build the angela one but after consideration (and the fact I have 240 mains and the availability of [reasonably priced] HT TX's here), I thought I would build one with no R's or C's in the signal path.
I just like the look of this one.
Thanks for that info.
I was initially going to build the angela one but after consideration (and the fact I have 240 mains and the availability of [reasonably priced] HT TX's here), I thought I would build one with no R's or C's in the signal path.
I just like the look of this one.
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