5881's in MK IV?

[stokes]

Russ, as long as they match the bias in your amp they are okay,this is a good reason to have an adjustable bias in the Boogie,lets you use those NOS tubes.

 

[Russ]

:? Looks like I gotta get the adjustable bias done...

 

[stokes]

Just be aware the MKIV is a little tricky,with the simul-class.Try and seek out jamme61,I helped him out with his,he can give you a first hand account of the pitfalls.

 

[Russ]

FWIW, shep,.... my Ampeg VL head has 7025/12ax7 painted next to all of the sockets for the preamp.

 

[Antoine]

I have always used my MarkIV with 4 6L6's. Some weeks ago, i've found a deal on 4 NOS 6L6's General Electric, i've mounted them on the MarkIV and i can tell you these are the best 6L6 i have tried, the sound is very big, fat and still very clear with good harmonics, they are the only NOS tubes i have, exept for the 2 Phillips JAN 12ax7.

 

[welshboogie]

A true 5881 is a 25 watt tube. The Sovtek 5881 and 5881 WXT are 30 watt tubes and basically a 6L6 is a small bottle. They may be darker in tone by design. The 5881 when it all comes down to it is a really good sounding tube. The STR-420 was the Shuguang/Sino 6L6 as you guys mentioned. I hate to say this, but it was and awsome sounding tube. It sucked as far as lifespan, but it was awesome. I still have 4 NOS 420's.
Two straight and two coke bottles. For me, in the MK IV the 420's are incredible in all four sockets. I found the best tone and balance in using the GT 6L6GE American Made and the GT 6CA7GE American Made. They combine to give me a huge simul class tone. I also run these in the IIC+ Simul Head with great results. The other C's have a combo of old production Svetlana 6L6GC's and EL34's. These are very well balaced as well, but are a bit brighter with the EL34's over a true 6CA7. The 6CA7's also blend well with Mesa STR-415's and Phillips 7581A's. They are an EL34 basically with a huge bottom and smooth top. My favorite tube for EL-34's in Simul's is a NOS Tesla ( Pre JJ) EL-34. I would give a kidney to get a hold of two more. The JJ E34L is it's modern couter part, but they make it wrong. It's closest duplicate is made by JJ on the GT tooling as the original has huge heat wings. Sadly, they do not sound as fat as the old Tesla's.

Have Fun !!! This can go on forever.

So I take the spare set of Coke Bottle 420's I had (in addition to the 4 already installed in my hardly used IVA) were a good find!!!

 

[Shep]

sorry yeah they are rca 7027 A...I also just pulled 12 very very old " made in england " BRIMAR's.. 12ax7 out of a box.. and a even older red RCA 12ax7.

Thanks for the info about the RCA's

Tom

 

[Russ]

So I take the spare set of Coke Bottle 420's I had (in addition to the 4 already installed in my hardly used IVA) were a good find!!!

I wish I had some to have as spares. Mine will be going and I have no way to replace the tone without finding someone that has them that wants to share because they are no longer produced.

 

[Boogiebabies]

http://www.srs-webstore.com/pages/shuguang.html

 

[Russ]

Thanks for the link Boogiebabies. Can you order up specific ranges like the Boogie graded tubes there?

 

[stokes]

Shep,if those Brimars are in good shape (not microphonic or noisy),you got some sweet tubes there.Same for that RCA AX7.I love NOS tubes.

 

[Shep]

most of them sound like they work..i have tried the Rca in my mesa in V1 and my clean was instantly a millon times better! wasn't as good for the higher gain channel's..


i haven't try the brimar's in my mesa yet i have only try them in the amp i got them out off...( a 1960's laney 100watt 6 channel PA head..) it also had phillips CA7's for the power setion..)there was a Ax7 on each channel then a at7 for the phase inverter and a ax7 for the echo loop or somthing..


about 5 of the brimar are working great..1 was is very loud and distorted and another is very weak.. i wish i had a pre amp tube tester and then i could really test them..

 

[stokes]

A tube tester will only tell you if they are good/bad.Even a good quality gm tester wont tell as much as putting them in the amp and hearing them.Put them in an amp give them a listen.Even if they dont sound good in a Mesa dont discount them,they may sound good in a lower gain amp like a Fender or Ampeg.A lot of NOS tubes wont be quiet enough for the hi-gain amps,but will be fine otherwise.

 

[6L6C]

For all of you guys on this thread that are using NOS power tubes.

Do you have a fixed or adjustable bias?

 

[Antoine]

Fixed bias.

 

[stokes]

Fixed,adjustable bias.

 

[igfraso]

A true 5881 is a 25 watt tube. The Sovtek 5881 and 5881 WXT are 30 watt tubes and basically a 6L6 is a small bottle. They may be darker in tone by design. The 5881 when it all comes down to it is a really good sounding tube. The STR-420 was the Shuguang/Sino 6L6 as you guys mentioned. I hate to say this, but it was and awsome sounding tube. It sucked as far as lifespan, but it was awesome. I still have 4 NOS 420's.
Two straight and two coke bottles. For me, in the MK IV the 420's are incredible in all four sockets. I found the best tone and balance in using the GT 6L6GE American Made and the GT 6CA7GE American Made. They combine to give me a huge simul class tone. I also run these in the IIC+ Simul Head with great results. The other C's have a combo of old production Svetlana 6L6GC's and EL34's. These are very well balaced as well, but are a bit brighter with the EL34's over a true 6CA7. The 6CA7's also blend well with Mesa STR-415's and Phillips 7581A's. They are an EL34 basically with a huge bottom and smooth top. My favorite tube for EL-34's in Simul's is a NOS Tesla ( Pre JJ) EL-34. I would give a kidney to get a hold of two more. The JJ E34L is it's modern couter part, but they make it wrong. It's closest duplicate is made by JJ on the GT tooling as the original has huge heat wings. Sadly, they do not sound as fat as the old Tesla's.

Have Fun !!! This can go on forever.

So I take the spare set of Coke Bottle 420's I had (in addition to the 4 already installed in my hardly used IVA) were a good find!!!

The Mark IV was designed around the STR-420.

 

[dodger916]

I didn't think you could use 5881's in any amp that calls for 6L6GEC tubes? I have a set of 5881's that I took out of a Zinky "Mofo". they're the "waffer" base 5881 tubes.

Yeah. Page 20 of the Mark IV manual. All 4 sockets or just the Class A's.

 

[Scary]

I prefer the 420 6L6's in mine over the 5881's. More power and crunch!

 

[stokes]

I didn't think you could use 5881's in any amp that calls for 6L6GEC tubes? I have a set of 5881's that I took out of a Zinky "Mofo". they're the "waffer" base 5881 tubes.

Be sure not to use older 5881's.The current productions are made to take the volts and current of the more modern 6L6GC's,the older ones cant.IMO the newer 5881's are not at all like the old stock versions,more like a relabeled 6L6GC.