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AUDIO FORUMS >> General Discussion and Support >> ? About Mod/ upgrade for SE 84C EX from 2007
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Message started by Morganc on 08/25/12 at 19:29:09

Title: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/25/12 at 19:29:09

I just picked up a used Zen 84C and have a few questions about it. I changed out the tubes to NOS and am loving it right now, but I want to take it to the max so I'm requesting help!

My amp says it was manufactured in 2005, serial number 608, though when I opened the amp it has a date on a little block of wood of 2007 signed S.D. And I assume that is Steve Correct? On the outside of the amp it says SE 84C EX.

I opened the amp to see how many and what size caps I would need to upgrade and there are many caps inside. Two pairs that say 0.33 and a few others in a larger size.

The question I have is:
1. Should I just send this amp to Steve for the V Cap upgrade and the Hazen Grid Mod all together or can I do it easily myself?
2. How to identify the caps that need to be upgraded? Should I post photos here?
3. How close sonically is this unit to current production? Or put another way, what kind of improvement will the mods bring out?
4. Any idea on cost for this level of upgrade with the hazen Grid Mod and the V Caps if I send it to Decware?

Thanks

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by deucekazoo on 08/25/12 at 20:23:34

At the bottom is a dedicated forum for the older 84C amps. Read through them and you will find what you need. Here is a link to one of your questions.

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1332613400

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/25/12 at 20:38:54

Thanks Deuce. I searched the forums but somehow missed that thread. So now I know what size V caps I need and where they go, can anyone tell me how far this will get me sonically to the latest model? I.e what else can I do and what's the biggest bang for the buck improvements?

Thanks again,
M

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Lon on 08/25/12 at 21:11:00

My guess is that the machine was checked out and "reassigned warranty" in 2007 by Steve.

Also from what I saw listed as costs I'd say it would cost about 250 for the VCaps install and 100 for the Hazen Grid mod.

Personally, I think Steve chose excellent parts for these and I would not modify other caps. etc.

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/25/12 at 21:32:47

Thanks Lon. I have a simple question. Are the V caps that Steve uses the Copper or Teflon versions? I'm pretty sure I can install them myself.

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Lon on 08/25/12 at 22:08:43

That I don't have the answer to.

If you can install those, you can probably do the mod yourself as well!

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by sberger on 08/25/12 at 22:11:09

Steve uses the teflon Vcaps in the Torii so I assume it would be the same in his other amps.

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/26/12 at 02:25:47

Perfect. That's exactly what I thought.

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/26/12 at 02:27:12

Is there a paper on the HGM Part I? I found the part Ii, but I'm assuming the actual mod description is in Part I, no?

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Lon on 08/26/12 at 02:35:10

?

https://www.decware.com/newsite/paper145.htm

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by clowkoy on 08/26/12 at 12:41:07

There are no 0.33uf capacitors. It's 33uf for the power supply.
The coupling caps are 0.1uf 600 volts. These are the ones you're going to replace with vcaps, about $120 including shipping from vh audio. the hazen mod are two 0.1uf 400 volts polyester , solder to pins 3 and 6 of the output tubes. Very easy mods.

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/27/12 at 00:09:19

Thanks. I ordered both sets of caps. Can't wait to do the mod!

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/31/12 at 07:42:04

Alright guys, need some help.
1. I have identified the output pins and ordered the caps for the CCemod. That looks easy.
2. For the VCap mod, I ordered and have received the V Caps 0.1 uF from VH Audio (great price, rapid service, and shipping!), but my amp is different!
3. I have no green caps at all. Mine is an 84-C-EX and it has two black caps at 3.3 uF and two yellow caps at 0.33 uF and are GE caps. I just assumed that earlier I had misread something, but in fact these are the caps I have.

Is it safe to assume that the GE caps are the upgrade for the CEX model?

How best to proceed at this point?

Thanks,
Morgan

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 08/31/12 at 07:51:19

Photo of caps: Black on the outside are Solen 3.3
Yellow are Ge 0.33

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 09/01/12 at 03:58:00

Tried to call Steve and just missed him today....anyone?

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 09/01/12 at 19:04:55

Bueler?

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by clowkoy on 09/10/12 at 08:05:35

Hi!
First, download a schematic of the zen or the zen kit. I'm sure the yellow caps are the coupling caps. Those caps connect from pins 1/6 of the input tube to pin 2 of the output tubes. You can go ahead and replace those caps with the vcaps. Check also the value of the cathode resistor (the one with a bypass cap). The new value is 150 ohms. Older units have 100 ohms IIRC.
And one more, the green leads of the vcaps connect to pins 1/6 while the reds connect to pin 2 of output tubes.

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Steve Deckert on 09/11/12 at 03:35:56

The .33uf caps in your amp are in fact the coupling caps and can in fact be replaced by .1uf caps. The EX in your serial number means you have the EX transformers, ie., the ones for 8 and 16 ohm speakers, where the original transformers are for speakers between 2 and 8 ohms, 4 ohms being ideal.

Steve

Title: Re: ? About Mod/ upgrade for SE 84C EX from 2007
Post by Morganc on 09/11/12 at 04:05:54

Thanks Steve,
I have the caps but I'm considering just selling the amp and upgrading to the new Super Zen. I think that is the best way to go. How can I get on the list for the new amp?