3-Channel DR current draw range? Need Advice Please

Does anybody know what the current draw range would be for this amp? I have found that the current draw range for the Mark series falls in the 17-25 range based on the plate current measurement system. I have a new quad set of SED =C= EL34's that have 38 written on the box and was wondering if they would be "ok" to use in this amp. I went ahead and installed them last night and played for a few hours without noticing any adverse reactions other than a great sound but I do want to be sure that I don't do any damage to the amp by running them. Any and all help, assistance, and advice are greatly appreciated!

btw... I am running the amp in the "Spongy" mode.

The only way to check is to get a Weber Bias Rite or Ohm Meter with a tube socket adapter. I think that the 38 on the box would have to do with the testing and grouping of the tubes, not how they would bias up in an amp. I have bought several tubes with the box numbers 29, 34, 37, 73, ext. and supposedly they were all for Boogie.
If you like your sound and the tubes are not burning red on the plates, then go for it, Spongy and Tube Rec drops the voltage way down anyway, so it should be safe.

So there's no need to set the bias properly? Just swap the tubes and it's all set (and flip the back switch to EL34 of course )?
My current JJ 6L6's are getting old. I might try these Winged C EL34 too.

junior said:

So there's no need to set the bias properly? Just swap the tubes and it's all set (and flip the back switch to EL34 of course )?

Click to expand...

As long as the tubes fall into Mesa specs (or under 65-70% MPD), yes, just plug and play. Mesa's are non-adjustable fixed bias anyway, so in stock form, there is nothing to adjust.

IMO- When you look at the price of a bias probe (Bias-Rite etc.) vs. the cost of a Mesa amp, it is foolish not to own one if you are trying non-Mesa tubes.


Dom

gmcelroy said:

Does anybody know what the current draw range would be for this amp? I have found that the current draw range for the Mark series falls in the 17-25 range based on the plate current measurement system. I have a new quad set of SED =C= EL34's that have 38 written on the box and was wondering if they would be "ok" to use in this amp. I went ahead and installed them last night and played for a few hours without noticing any adverse reactions other than a great sound but I do want to be sure that I don't do any damage to the amp by running them. Any and all help, assistance, and advice are greatly appreciated!

btw... I am running the amp in the "Spongy" mode.

Click to expand...

Most tube stores will help you get mesa "spec'd tubes .
Here is the GT to mesa spec chart .

The bottom line here is;

Lower numbers will start to distort at lower volume settings on your amp, and have more dynamic touch and feel.
These are the GT 1-3 range, and the Fender "blue" painted tubes. Many Jazz or Blues players like this range, and
they work well for recording where levels are going to be lower, or in smaller venues.

Medium numbers are the most versatile, will drop into most amps and be very close to most factories bias settings,
and are the best general choice for most players wanting a versatile well rounded amp. These are the GT 4-7
range, and the Fender "white" painted tubes. The range of 4,5,6 are able to be used in Mesa Boogie fixed bias
amps, and on the Mesa scale convert roughly to:

Mesa scale Groove Tubes scale
Red 4
Yellow 4
Green 5
Gray 5
Blue 6
White 6

Nice to keep handy

/cheers

domct203 said:

junior said:

So there's no need to set the bias properly? Just swap the tubes and it's all set (and flip the back switch to EL34 of course )?

Click to expand...

As long as the tubes fall into Mesa specs (or under 65-70% MPD), yes, just plug and play. Mesa's are non-adjustable fixed bias anyway, so in stock form, there is nothing to adjust.

IMO- When you look at the price of a bias probe (Bias-Rite etc.) vs. the cost of a Mesa amp, it is foolish not to own one if you are trying non-Mesa tubes.


Dom

Click to expand...

Didn't know about this bias probe...

LerxstLee said:

gmcelroy said:

Does anybody know what the current draw range would be for this amp? I have found that the current draw range for the Mark series falls in the 17-25 range based on the plate current measurement system. I have a new quad set of SED =C= EL34's that have 38 written on the box and was wondering if they would be "ok" to use in this amp. I went ahead and installed them last night and played for a few hours without noticing any adverse reactions other than a great sound but I do want to be sure that I don't do any damage to the amp by running them. Any and all help, assistance, and advice are greatly appreciated!

btw... I am running the amp in the "Spongy" mode.

Click to expand...

Most tube stores will help you get mesa "spec'd tubes .
Here is the GT to mesa spec chart .

The bottom line here is;

Lower numbers will start to distort at lower volume settings on your amp, and have more dynamic touch and feel.
These are the GT 1-3 range, and the Fender "blue" painted tubes. Many Jazz or Blues players like this range, and
they work well for recording where levels are going to be lower, or in smaller venues.

Medium numbers are the most versatile, will drop into most amps and be very close to most factories bias settings,
and are the best general choice for most players wanting a versatile well rounded amp. These are the GT 4-7
range, and the Fender "white" painted tubes. The range of 4,5,6 are able to be used in Mesa Boogie fixed bias
amps, and on the Mesa scale convert roughly to:

Mesa scale Groove Tubes scale
Red 4
Yellow 4
Green 5
Gray 5
Blue 6
White 6

Nice to keep handy

/cheers

Click to expand...

Although you can make the bias adjustable with Modifications , as mesa comes with " fixed bias " except
the EL34s on a Road king which do have the bias pot already in place .you can simply use this chart thus
not voiding your warranty . Although mesa will say you must use mesa tubes . If you get mesa " spec'd "
(used lightly ) as a term .
If you buy the bias rite or any other of the bias " tools " if you do not modifiy your bias , you cannot
change it any way . So spend money to look at the bias and roll tubes or , simply use a tube seller
that will mesa spec them for you , or if you like some of the groove tubes just grab a set in the proper range.
If you are not going to modify the bias to make it adjustable , then do not waste the money on a bias meter.
Most amp techs or music shops will tell you those figures for the price of a bench charge .
Yet you still have a " fixed bias " . Spend your money on tubes in spec , your bias is fixed .
Sure it is nice to check it , but if you are not going to make it an adjustable bias supply , then
you are buying an expensive tool . For example , you can check the air pressure in your tires really cheap ,
and you can change the pressure also really cheap .
Well hope this helps a bit more .
If you grabbed a quad of NOS EL-34s Siemens Brand from mesa themselves for $300.00 bucks you get a warranty
and aside from NOS mullards ect , siemens are a great sounding tubes imo . The last of the old tooling and
metalurology soon to be gone .

Hope this helps .