Forums - Print Page

Forums
https://www.decware.com/cgi-bin/yabb22/YaBB.pl
OLDER DECWARE GEAR SUPPORT >> SE84CS, SE84ZS >> Valves for SE84ZS
https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1332326600

Message started by Nick OSiris on 03/21/12 at 11:43:20

Title: Valves for SE84ZS
Post by Nick OSiris on 03/21/12 at 11:43:20

What combination of valves are people enjoying in the SE84ZS? I got mine second-hand on Ebay and I'm convinced that the valves included in the sale aren't the best they could be. I'm ok as regards the input stage as I have some nice Siemens CCa and E88CC already.

What do I want to be looking for in a rectifier? What should I avoid? The one I have is a Ruby 5U4GC.

And how about the power valves? I've got the standard Russian military ones and also a pair of AEG ECL86 that I can't find too much about on the net. Are they a drop-in replacement on the SE84ZS?

Any assistance would be most welcome.

Title: Re: Valves for SE84ZS
Post by Rivieraranch on 03/21/12 at 12:44:57

I don't think ECL86's are appropriate in this circuit. Get some 6P15P-EV or SV83's.

Title: Re: Valves for SE84ZS
Post by dank on 03/21/12 at 21:27:51

In my Zkit1 I've found no power tube I like better than the Russian 6p15p. Bought mine on Ebay for about $2 each.

Dan

Title: Re: Valves for SE84ZS
Post by Rivieraranch on 03/21/12 at 22:33:26

No wonder; the amp is designed around the 6P15P-EV

Title: Re: Valves for SE84ZS
Post by Nick OSiris on 03/22/12 at 02:27:14

Many thanks guys, this is all useful info.

Anyone have a quick word to say about rectifiers? The manual suggests that the choice of rectifier can have a big influence on the sound.

Title: Re: Valves for SE84ZS
Post by dank on 03/23/12 at 15:25:33

I prefer solid state rectification from a pair of 1n4007 diodes to the rectifier tube. The Zkit1 uses this form of rectification. It yields higher voltage out and slightly more power. I think it adds more punch to the sound, or a crisper , more detailed sound. I've experienced no problems from the solid state rectification...some say that the fast turn on is hard on tubes, but I've seen none of that. You can make a solid state rectifier out of an old rectifier tube...just break the glass, be sure to cut the heater wire or just let it burn up, and solder a couple 1n4007 diodes to the appropriate pins, diode anodes (no band) to tube plates, diode cathodes (band) to tube filament pins (cathodes).

Dan

Title: Re: Valves for SE84ZS
Post by Rivieraranch on 03/24/12 at 01:34:50

You could buy an SS rectifier replacement to see how it sounds. Then do a shootout between different kinds of 5U4 rectifiers.

Title: Re: Valves for SE84ZS
Post by Nick OSiris on 03/26/12 at 14:37:04

Once again my thanks to those that have made suggestions. I'm getting close now I reckon, and I'm getting used to the SE84ZS 'sound'. It's certainly winning in the 'tuneful bass' category, and that bass is going as deep as I need it to go (one crucial factor for me). The Audion is still ahead in various of the "S" categories however: soundtage, separation, smoothness... but it's a close-run thing.

The Fullmusic 300B/c in my Audion that look down on the SE84ZS snorted with derision when dank suggested that a $2 power tube was the best I could do (the Fullmusics cost someone over $400) but he has a point and as has been stated above the circuit was designed around the 6P15P-EV.

One slight minus point that I won't be able to solve with valve rolling is the max volume available. I'm frequently listening at top volume, and whilst that's perfectly delicious and satisfying there are isolated occasions when I just want a little more. Which is one reason why I may end up keeping both amps for the time being.