Bias rating of the EL34 tubes in your Friedman BE 100?

T

TheGhost

New member
I am trying to find out what the range is concerning "bias rating" numbers for stock EL34 tubes in Friedman BE 100 amps. If everyone who owns one could please take a few minutes to read the number written on top of the four EL34 power tubes in their BE 100 and post them, I would sure appreciate knowing the results. If the tubes are original then they came from ARS and the number will be written on the top of the tubes in felt pen. It will take less than 3 minutes and will be very helpful.

Please do not post what setting to bias the amp at, that is something entirely different.

Thanks.
 
A friend of mine, whom is looking to buy one, contacted the seller of one on Ebay right now, and that BE 100's tubes are 49.
 
No markings on mine. I had 2 tubes go bad and replaced the whole set. According to Dave the best bias is 30 to 32 ma per tube.
 
Yes, you are correct about biasing at 30 to 32ma, but that is something different.
What I am after is everyone's " Bias Rating" marked on the tubes, not what to bias the amp at.

Thanks for looking though, I do appreciate it.
 
What's the point - First, any mA rating you get from a seller won't correspond to the mA reading you'll get in an amp. The rating is only applicable to the sellers test equipment and is used for matching the tubes, and possibly establishing a low, medium, high rating.

Second, the safe range depends on your amp and it's plate and cathode voltages.
 
lester":2hn4pd5r said:
What's the point - First, any mA rating you get from a seller won't correspond to the mA reading you'll get in an amp. The rating is only applicable to the sellers test equipment and is used for matching the tubes, and possibly establishing a low, medium, high rating.

Second, the safe range depends on your amp and it's plate and cathode voltages.
Click to expand...

Since the stock tubes all came from ARS the data collected will be applicable because the same seller tested the tubes. If it were different companies supplying the tubes, then of course it wouldn't be, but that is not the case. All I'm concerned with is the range of tubes coming from ARS and determining the low medium and high bias ratings for stock tubes in a BE 100. I have my reasons for wanting to know.

Second, I'm not concerned with the safe range.
 
I think Dave has mention in the past to do this, not sure if it has changed.

bias between 30 and 40ma, 32ma at factory with 120V wall voltage, plate voltage around 470vdc.

I think mine was in the middle depending on the tube set. Good to go.
 
mdc1mdc11":2gj36pkn said:
I think Dave has mention in the past to do this, not sure if it has changed.

bias between 30 and 40ma, 32ma at factory with 120V wall voltage, plate voltage around 470vdc.
Click to expand...

Thank you, but this is not about biasing the amp.
This thread is about the "Bias Rating" of the stock EL34 power tubes.
 
yes, 58 n ARS

i just ordered two sets n with chinese preamp tubes. They will be delivered tomorrow. ARS said the number written on top is the "mu" rating
 
Mine had mid 45 as I recall since changed them to JJ labeled.
Ok now that you have gotten a bunch of input how about letting us know "your reasons" for wanting to know....seems fair to me :D
 
I am waiting to get some information from a tube supplier before I know for sure if it's going to happen because it will involve them.

I still want to know what the absolute lowest and highest stock "bias rating/mu" numbers are. So, please keep them coming.
 
Got the new tubes today. The power tubes are JJ/Tesla. I fucked up a little as ordered from work an mistakenly ordered "56" in insted of "58". Oh well. Close enough. Bias at 32mA as Dave said and call it a day!
 
Equ1nox":365fdkal said:
Got the new tubes today. The power tubes are JJ/Tesla. I fucked up a little as ordered from work an mistakenly ordered "56" in insted of "58". Oh well. Close enough. Bias at 32mA as Dave said and call it a fucking day!
Click to expand...

Like you said, they will be close enough.

It's when you have 35s and switch to 58s that you really start to notice a difference. Even 35s to 42s is different. Which makes you wonder what your amp would sound like with different "Bias Rated/mu Rated" tubes. What if you like the sound or firmness of 42s better than the 35s? Or the other way around.

It would be cool if someone posted audio clips with different "Bias Rated" tubes (but, all still JJs from the same supplier) in the same amp, so you could hear the differences and decide which tubes you preferred in your BE 100. A firmer tube or one that breaks up sooner. ;)
 
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