• New Sponsor: ShipNerd, Ship Your Gear with Us... for less! Click Here.

Tung Sol 7581A for more 6L6 headroom?

kwicked

Senior Member
Messages
3,669
Are these the simple answer to higher headroom in a 6L6 amp? Seems like its never that simple with tubes..:confused:
They look pretty recent, anyone used them? Good value or better off with NOS ( I like value over price and if its 2x price, but 4X durability, I'm in)
Any thoughts on higher headroom 6L6GC's appreciated
 

DaveKS

Member
Messages
16,704
Well I've only had experience with old stock ones, all I can say it's going to be amp circuit dependent on how much extra you can get out of them. But even a amp that can make use of them your only talking about 5-7w for a pair extra, that's really just a drop in the bucket in grand schem of things when talking headroom. You can get 10x the mileage out of a more efficient speaker when seeking more headroom.

Now tone wise wise and reliability wise they are beyond awesome, the Godzilla's of 6L6, take a direct hit from a nuke and get up and proceed to burn your city to the ground reliable. The old GE 7581a are one of my favorite tone monsters, to bad their in the unobtanium price range these days. Same for the old Philips, their a little smoother, warmer in tone but $$$$$ if you can even find them.
 

riffmeister

Silver Supporting Member
Messages
16,670
I've tried new manufacture Tung Sol 7581A's. I like them.....big, full, crisp sounding tube. They are rated for 30W like other 6L6CG's, so I'm not sure about the more headroom claim by the retailer.
 

stark

Silver Supporting Member
Messages
3,407
I'm a big fan of 7581A, but I'd like to hear if the new ones are actually the same construction.
 

DaveKS

Member
Messages
16,704
I've tried new manufacture Tung Sol 7581A's. I like them.....big, full, crisp sounding tube. They are rated for 30W like other 6L6CG's, so I'm not sure about the more headroom claim by the retailer.
I'm a big fan of 7581A, but I'd like to hear if the new ones are actually the same construction.
I seriously doubt it on either count, just marketing voodoo trying to cash in on the 7581a moniker and what it actually did stand for back in the day. Maybe Blue Strat or other dealers who've actually tested the new ones will chime in.
 

Doug's Tubes

Platinum Supporting Member
Messages
10,660
I've tried new manufacture Tung Sol 7581A's. I like them.....big, full, crisp sounding tube. They are rated for 30W like other 6L6CG's, so I'm not sure about the more headroom claim by the retailer.
According to New Sensor's tech support, I spoke to Otto when I was there a couple of weeks ago and he said the added heat fins increase the plate dissipation to 35 watts.
 

RussB

low rent hobbyist
Messages
11,157
The power supply in your amp will have a big influence on how much "more" headroom you can achieve.
 

riffmeister

Silver Supporting Member
Messages
16,670
According to New Sensor's tech support, I spoke to Otto when I was there a couple of weeks ago and he said the added heat fins increase the plate dissipation to 35 watts.
Ah, my bad. I was thinking of the Tung Sol 7581 which is being phased out......I bought a set a few months ago and the spec sheet said 30W plate dissipation. The newly introduced 7581A has a 35W rating as you say.
 

Doug's Tubes

Platinum Supporting Member
Messages
10,660
Ah, my bad. I was thinking of the Tung Sol 7581 which is being phased out......I bought a set a few months ago and the spec sheet said 30W plate dissipation. The newly introduced 7581A has a 35W rating as you say.
That's the old spec sheet, New Sensor hasn't even updated their website for the change in the tube. Here's the info on it, Russia made the change many months ago without telling anyone. They frequently update their tubes.

I can say one thing about these 7581A's, the idle current is much higher than a 6L6GC.
 

drbob1

Gold Supporting Member
Messages
29,207
If the B+ remains the same, won't the headroom basically be the same? You're not getting a more efficient tube, just a tube that can run hotter if the amp is set up for it.
 

Blue Strat

Member
Messages
30,243
I seriously doubt it on either count, just marketing voodoo trying to cash in on the 7581a moniker and what it actually did stand for back in the day. Maybe Blue Strat or other dealers who've actually tested the new ones will chime in.
Haven't tested them. Unwilling to take the risk of buying 100 of any unproven item. I've been burned before.

In general, 7581As will only give more headroom in an amp that's able to provide more power than 6L6GCs can produce. Power starts in the power supply and headroom is directly related to power.

Since the brand name is a fake I wouldn't assume that the tube number is legit either.
 
Messages
37
The 7581 is the 6L6's big brother.I like the Sylvania 7581's in my early Two Rock custom.I would try the China 6L6's and JJ's first,matched with medium PC #.
 

mrwhipple

Gold Supporting Member
Messages
952
The NOS GE 7581A is a really nice tube. Big and punchy.

I've had them in a /13 EDT and they sound amazing.
 

Conroy

Member
Messages
52
I'm curious about the Tung Sol 7581A too. Anyone had a chance to try them yet? They're described as having a rich detailed sound. I wonder if the extra heat could cause problems in the amp down the road. I would like to use four in a Fender Twin Ultra Linear. Do you think this would be a good match? I'm not seeking more headroom just durability and sound quality.
 
Messages
6,864
I'm curious about the Tung Sol 7581A too. Anyone had a chance to try them yet? They're described as having a rich detailed sound. I wonder if the extra heat could cause problems in the amp down the road. I would like to use four in a Fender Twin Ultra Linear. Do you think this would be a good match? I'm not seeking more headroom just durability and sound quality.
According to some sources they are truely uprated to 7581A specs now. This means they're actually 35W worth of bottle a pop, thus dissipation levels for the 6L6GC is bound to be a bit cold for it. On the other hand the higher max output does provide better dynamic properties as well.

Then personally I'm very much a fan of the TAD 6L6GC-STR for this context. Very nice push, likable dynamics with it and holds up quite well, in my experience. It is compared to the 7581 by Mr TAD himself and I'm bound to agree, although of course it's still rated for 30W max.
 

zenas

Member
Messages
8,872
Remember7591s have a different pin out than 6L6s. Not directly interchangeable.
Getting 7591s and 7581s mixed up will result in smoking parts. Or just blowing a fuse if you're really lucky.
 






Top Bottom