Ampeg SVP-CL Tube Recommendation?

[svtb15]

I had that preamp for about 1 week.. I LOVED the sound of it . But it hardly had enough gain to drive my crown or Carvin power amp so i returned t. I found out later that had a MOD to up the gain....
The original tubes for that preamp were 2x 12ax7 and 2x 12au7 IIRC.. The mix was used t replicate the old 12DW7 configuration of the original SVT amps

My FAVE Ampeg SVT pre was the SVTll-P.. The same pre in the NON PRO svt 2 and svt 3 non pro amps. Great... And had plenty of gain.. I saw them on ebay today... I should have bought a used one for $75 a few years ago They are way more than that now

Thank you smo....extremely informative.

Well... got the svp-cl a couple of days ago (slm 2004)....fired it up, to my modded ampeg V4 Guitar 4x12 cab (now 1kw@4ohm) {& yeah..i know it 'can' be a mudbox with the mod, if not properly eq'd or driven..but that's another story...}
....& of course, via my BGW 750-F Power Amp...

.....and....ok...

....let's just say i can get more 'output', from my ******** deaf-mute grandma with tape over her mouth....
{note: no grandmothers were actually harmed or defamed during this post....}

seriously....jeez....i had to dime the master and (just about) dime the 'input gain' all to just to drive my bgw.
..and i had to goose the vol on the power amp way more than i'm used to...
{...i dunno my 1979 solid state ashly sc40..KILLS with the bgw}

{but before you think i'm gonna bash the svp-cl,..chill }

I immediately popped the hood on the svp, and found these tubes; {from lft to rt}

[Invalid or Expired Link Removed]
[Invalid or Expired Link Removed]

Mojo Tone {"electronic tube"} 12AX7A-MC [2x];
GT 12AT7 {ECC81/6021} [2x]

first of all...12AT7's????...i thought they were supposed to be "12AU7's" on the right.
and "Mojo Tone"???....who the hell are they?....
....sounds like Kellogg's Cereal went into the electron tube business while i was away.....

Now... i can still hear the 'character' of this pre, even through these sh%^&ty tubes....
....it's a 'clean' ampeg svt voice , (the 'tubes' issue is an easy fix...we all went into that already...thank you)
....& it's a keeper, if i can fix the overall "output"... (or is the "crappy tubes THE" output issue?...anyone?)

Was the seller's, "Tubes are prob shot from laying around..." jazz, just an act?...
...for the fact that he really raped it of the stock tubes?....or am i off base with things?...

I'm ignorant & confused...(but still fly.... )

 

[Jim C]

Thanks bluesrx...& i'm gonna def look into that mod...

Jerold sent me to a shop who could do a perfect job on this mod; something like 7 resistors get changed; about $200.

They work perfectly with an amp that has a .775 Volt sensitivity; the Peavey IPS series and the Crest CA series fit this requirement.

I used a dbx compressor to raise the gain to drive a 1500 watt Ampeg power amp for crazy headroom.

Back to tubes:
Everybody has an opinion but very few have spent hours trying out expensive tubes and taking notes.
Generally speaking for me (and a few other guys who's opinions I trust on this site) long plate 12AX7's are very musical and used US tubes are available.
If you really want to get into it, I like used Telefunkens, Mullards, and Amperex tubes for both tone and ridiculously long life. I've got tubes from the early 60's that sound incredible and they were all removed from old gear that needed expensive repair parts. Many of thes tubes are rebranded with a different name.

As far as new tubes; I think they are just OK if you are particular about tone. There is plenty of new trash out there.
Many say JJ and the Mullard copies are OK.

 

[MJ_Sotti]

So I opened up my SVPCL and there 4 12AX7's in there. The one and two are groove tubes, three and four are sovotek's. I get a little decay when sustaining a note...New tube time?

 

[JimmyM]

Probably. Sounds like someone went in there and tried to boost available volume by using 12ax7's in the 12au7 slots. Don't know if all are bad but I'd at least get rid of the two 12ax7's that should be 12au7's.

 

[MJ_Sotti]

Mike in Chicago=dinosaur...