UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - GZ34

Ian - G4JQT · 20th Oct 2019, 6:49 pm

Update:

Well I got a pair of GZ34 valves branded "JJ" from karltone.co.uk

With the original GZ37 volts either side of the Wadar PSU choke was 260 and 270V. With the GZ34 it's now 285/295 with a noticeable increase in volume.

I know in an amp the rectifier valve has no significant effect on sound quality if working properly and I could have used silicon diodes, but I wanted the keep the cct original using valves. And there's no noticeable arching in the rectifier if the amp is switched off then on again with the GZ34.

Note for anyone joint this thread late; this Gerry Wells amp used a GZ37 rectifier which theoretically at least was not really up to the current surge of the PSU electrolytic capacitors. Maybe Gerry decided it practice it didn't really matter...

20th Oct 2019, 6:49 pm	#18
Ian - G4JQT Octode Join Date: Jun 2004 Location: Reading/Fakenham, UK. Posts: 1,323	Re: GZ34 - recommended brands? Update: Well I got a pair of GZ34 valves branded "JJ" from karltone.co.uk With the original GZ37 volts either side of the Wadar PSU choke was 260 and 270V. With the GZ34 it's now 285/295 with a noticeable increase in volume. I know in an amp the rectifier valve has no significant effect on sound quality if working properly and I could have used silicon diodes, but I wanted the keep the cct original using valves. And there's no noticeable arching in the rectifier if the amp is switched off then on again with the GZ34. Note for anyone joint this thread late; this Gerry Wells amp used a GZ37 rectifier which theoretically at least was not really up to the current surge of the PSU electrolytic capacitors. Maybe Gerry decided it practice it didn't really matter...