New valves/tubes for the MarkIV?

petejt

Active member
My amps have been in storage for almost two years, so I've barely got the chance to play them. They are now in a small room where I have moved to, so I get to play them more often. And I've noticed that the power amp of the MarkIV seems a bit lacking. The preamp valves are fine as I tested the sound through a separate power amp.

Currently I have a pair of JJ 6L6s and Svetlana EL34s in the MarkIV. It used to sound great on its own with a lot of punchy mids.

But now I think I want a more full "hi-fi" sound that I can sculpt however I want, as I want a scooped-mid crunchy sound using the graphic EQ, and a squawky-mid sound using the effects loop and effects. So I guess I need a quartet of 6L6s.

I remember the praise about Winged Cs from about 8-9 years ago which seems to have dissipated. Doug's Tubes doesn't even stock them anymore.

What could be the best to use for a full, powerful sound without going to 6558s or the new old stocks? Just a set of Ruby 6L6s? If so, which ones?
 

ChurchHill

New member
Unfortunately, Winged Cs are out of production. As far as new stock, there seem to be good reviews of TAD 6L6GCs and TAD 6L6WGCs. Last time I retubed my Mark IV, I just used Mesa tubes (too lazy to want to mess with biasing them at the moment).
 

Snave

Active member
STR440s are a fine 6L6. Ruby 6L6GCMSTR is the same tube if you want to save some money.
 

psychodave

Well-known member
I’ve tried the following and in my Mark IVa this past week: Winged C’s, 420’s (both small and big bottles), 430’s, 440’s and 5881’s and I like what each has to offer. I also tried EL34’s (outside sockets) and have currently settled on Winged C’s and EL34’s. I found the 440’s to be a little dark, 430’s a little bright, 420 (big bottles) a bit too much bottom end. The Winged C’s were good, but a little loose in the bottom end. Using EL34’s helped that.
 

Racerxrated

Well-known member
psychodave":1b5bhczr said:
I’ve tried the following and in my Mark IVa this past week: Winged C’s, 420’s (both small and big bottles), 430’s, 440’s and 5881’s and I like what each has to offer. I also tried EL34’s (outside sockets) and have currently settled on Winged C’s and EL34’s. I found the 440’s to be a little dark, 430’s a little bright, 420 (big bottles) a bit too much bottom end. The Winged C’s were good, but a little loose in the bottom end. Using EL34’s helped that.
Have you tried your 415s? Or didn't they make a difference in the IV?
 

psychodave

Well-known member
Racerxrated":1w58fvtx said:
psychodave":1w58fvtx said:
I’ve tried the following and in my Mark IVa this past week: Winged C’s, 420’s (both small and big bottles), 430’s, 440’s and 5881’s and I like what each has to offer. I also tried EL34’s (outside sockets) and have currently settled on Winged C’s and EL34’s. I found the 440’s to be a little dark, 430’s a little bright, 420 (big bottles) a bit too much bottom end. The Winged C’s were good, but a little loose in the bottom end. Using EL34’s helped that.
Have you tried your 415s? Or didn't they make a difference in the IV?

I tried 415’s as well. They were cool, but I preferred the newer tubes. The 415’s were clearer but felt like the amp lost some gain.

I should take a picture of the mess of tubes. I have them all lined up behind the amp. lol
 

SpiderWars

Well-known member
psychodave":1t5vd7qw said:
I tried 415’s as well. They were cool, but I preferred the newer tubes. The 415’s were clearer but felt like the amp lost some gain.

I should take a picture of the mess of tubes. I have them all lined up behind the amp. lol
That's what I liked about them and didn't like about EL34s in the outer sockets (mids were too snarly for me, some people like that though). For new production I liked the big bottle TADs and when I sold it I put like-new short bottle TADs in it that I'd had for quite a while. I just never found the right amp for the short TADs. But I don't think I tested as extensively as you did. I did try JJ and Tung Sol.
 

rbasaria

Well-known member
psychodave":1pj1i6t8 said:
rbasaria":1pj1i6t8 said:
Ive been using Sovtek 6l6s in everything these days. They sound great in my Mark IV.

WXT, WXT+?

One of those...I don't remember. Would check, but the amp is all boxed up right now since I am selling it.
 

Rex Rocker

Well-known member
AFAIK, only the Sovtek 6L6's are called WXT+'s. It should be those. If they're called WXT (not +), then they're 5881WXT's, not 6L6's.
 

psychodave

Well-known member
Rex Rocker":2llqbf3k said:
AFAIK, only the Sovtek 6L6's are called WXT+'s. It should be those. If they're called WXT (not +), then they're 5881WXT's, not 6L6's.

Ive seen both and they look almost identical. Usually the 5881 has the waffle plate near the pins.
 

petejt

Active member
I've come across a quartet of JJ 6L6s so will grab them in a week or so. Then hopefully I can get some clips up!
It's been ages since I've been able to crank this thing and set up the mic.
 

bgh

Member
I use 6L6s in the inner slots and EL34s in the outer. Sounds very nice when I run in Simul-Class mode.

But, I cannot recall what brand they are. I think they are TAD. I will check next time I use it.
 
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