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Dubstep Girl's Massive 5AR4/5R4/5U4G Rectifier Review/Comparison! (Rectifer Tube Rolling thread)

Jun 8, 2023 at 3:37 AM Post #2,536 of 3,037
Jun 8, 2023 at 3:43 AM Post #2,538 of 3,037
Jun 8, 2023 at 12:05 PM Post #2,540 of 3,037
UntilThen said:
No problem. :)

Gibosi has a better chart with more rectifiers and I think of all people, he knows best about rectifiers... and of course Glenn but Glenn doesn't show up anymore.
Click to expand...
When I had my GOTL I never bought a rectifier without first getting Gibosi's seal of approval.
 
Jun 8, 2023 at 4:52 PM Post #2,541 of 3,037
UntilThen said:
Nope. Tomas who build my Odyssey told me the same thing. @gibosi will verify that.
Click to expand...

I measured voltage-drop for a number of rectifiers in my Glenn OTL, two 6AS7G and B+ = 257 VDC:

HEXFRED Solid state 1 volt
GZ34 / 5AR4 (Sittard) 13 volts
3DG4 (Tung-Sol) 17 volts
GZ32 (Mullard) 20 volts
53KU (Cossor) 22 volts
GZ37 (Mullard) 27 volts
5AW4 (CBS Hytron) 29 volts
5U4G about 40 volts (an average of several manufacturers)
 
Jun 8, 2023 at 5:04 PM Post #2,542 of 3,037
In Odyssey (picture below) Tomas advised me to use 5U4G when using EL12 spez and EL39 power tubes. For KT88, he said to use GZ34 preferably or any of the others. For KT88 in that amp, I prefer to use GZ34 which has a tighter tone and cleaner. GZ32 and 53ku adds some warmth that is nice, if that is what you want. I've also use 596 with very good results.

Anyone who tells me that rectifier doesn't change the sound, wouldn't convince me an inch because I can clearly hear the differences when I switch rectifier in this amp. It's the voltage sag and drop variation that affects the circuitry and the other tubes.

IMG_6404.jpg
 
Jun 8, 2023 at 5:05 PM Post #2,543 of 3,037
gibosi said:
I measured voltage-drop for a number of rectifiers in my Glenn OTL, two 6AS7G and B+ = 257 VDC:

HEXFRED Solid state 1 volt
GZ34 / 5AR4 (Sittard) 13 volts
3DG4 (Tung-Sol) 17 volts
GZ32 (Mullard) 20 volts
53KU (Cossor) 22 volts
GZ37 (Mullard) 27 volts
5AW4 (CBS Hytron) 29 volts
5U4G about 40 volts (an average of several manufacturers)
Click to expand...

Thanks!
 
Jun 26, 2023 at 7:27 AM Post #2,545 of 3,037
UntilThen said:
Isn't she lovely - Stevie Wonder.

IMG_6429.jpg
Click to expand...
That's some serious tube beauty (and investment). Still hoping to source some affordable NOS Telefunken EL12 Spez pentodes in the future. Which adapers are you using for the EL12's?
 
Jun 26, 2023 at 7:32 AM Post #2,546 of 3,037
Jun 26, 2023 at 7:40 AM Post #2,547 of 3,037
I'm currently trying out some French rectifiers from La RadioTechinique France. I own different vintages of the 5R4GYS, the precursor of the "famous" 1970's Philips 5R4GYS, which most likely is made by La RadioTechinique as well. I also own a La RadioTechinique 5R4GY. I'm testing these rectifers in my Woo Audio WA6-SE and Audio Note Paladin Silver Signature.

La RadioTechinique 5R4GY (construction is very similar to the RT 5R4GYS -> plates, getter, filaments and base):

IMG_0343.jpg


IMG_0344.jpg


1950's La RadioTechinique 5R4GYS:

IMG_0347.jpg


IMG_0348.jpg


1972 Philips 5R4GYS (black plates, dimple disc getter):

IMG_0345.jpg


IMG_0346.jpg


I will follow up with my (subjective) listening impressions at a later moment as these rectifiers unfortunately do require some burn-in to really open up.
 
Jun 26, 2023 at 7:50 AM Post #2,548 of 3,037
UntilThen said:
This one. You will never find affordable EL12 spez again.

https://www.ebay.com.au/itm/201784316782?
Click to expand...

I have tried the 4699 EL6 to EL34 6L6 adapters from the same seller in my Elekit TU-8200 in the past and they were a bit noisy:

https://www.ebay.nl/itm/191497663001?hash=item2c96267219:g:VPUAAOSwZ6ZiJsL1

Maybe I need to try them again as I remember some noise interference issues from my Wifi router (mostly with my Bottlehead Crack) at that specific time as well. Do you have noise issues with EL12 Spez adapters?

Do you have any experience with the AZ1 to 5U4G GZ34 5AR4 adapters? These might look interesting as well for using some nice AZ1 mesh rectifiers in the WA6-SE.
 
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Jun 26, 2023 at 8:00 AM Post #2,549 of 3,037
It's not the adapters. It's the tubes. Unless you buy new EL12 spez or get lucky with a good conditioned used pair, chances of being noisy is high. I have 3 new pairs of EL12 spez that are noiseless with Elekit TU-8200, Odyssey and Ultimate, using those same adapters.
 
Jun 26, 2023 at 8:03 AM Post #2,550 of 3,037
Tubegear said:
Do you have any experience with the AZ1 to 5U4G GZ34 5AR4 adapters? These might look interesting as well for using some nice AZ1 mesh rectifiers in the WA6-SE.
Click to expand...

I don't have experience with AZ1 rectifier or those adapters. I mainly use gz34, gz32, 53ku, 5u4g, 596, U52 and now on the new amp, 6bw4, ez80, ez81.
 
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