Thank you, Peter. I'll look over the sheets. If I can find 6P15P-EV's I will give them a try.Originally Posted by Hoerninger
Let me generally recommend, highly, this tool: http://www.duncanamps.com/tdslpe/
It is free, very easy to use, and the data sheet links are fantastic. The .exe file is tiny.
Download at the bottom of the page, then update the file when it starts.
Clark
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
All I know is it amazes me at the quality of things made decades ago.
Once I started using vintage tubes, there was absolutely NO going back.
My ears tell me some of the things from the past, well, they really had it right.
I LOVE vintage tubes.
scottyj
The long warmup may be a sign of future trouble...
IIRC, 6P14s and 7189s have slightly MORE heater current draw than standard EL84s. Don't know if it's ENOUGH more to cause a problem, but what you're describing, sounds a LOT like low heater voltage... which would be EXACTLY what would be happening, if there was too much draw. And the output tubes would be the first ones to be affected... pre-amp tubes have more "leeway" on heater voltage, than power tubes.
Thank you, Gordon, that is very interesting. I have the luxury for the moment to ask the amp's designer about this issue, so I will do so.
If low heater voltage is what is going on, and I don't doubt your observation for a second, he may have a workaround.
The only complication in all this is my CD player. It's a JoLida with tube output, and if past history is any indication, it may share in the blame here.
Clark in Peoria
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
It is common for NOS tubes to have better tonality than newly made tubes.
Most tubes, said or relabeled are made for guitar amps these days and the sound(lack of) defintely shows when used in music amps.
Glad you found good tubes, it is definetely not easy.
I have a small Admiral 2xEL84 amp and I had a lot of trouble finding good tubes until I found some NOS military grade tubes, and it sounds great now.
I have found the Russian Electro Harmonix EL84 to sound quite good in my Almorro A205 single ended pentode.
Just my 2 cents !
Ron
JBL Pro for home use!
They are very good tubes. A lot of listeners think the JJ's are the best sounding, but I like the E H tubes much better. All I'm saying is that in my amp the E H tubes were blown away by the old Soviet military spec tube. I just hope they don't destroy the amp...
Sounds like you are a fellow tubehead with a really sweet amp!
Clark
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
I think I'm about to have an occasion to test this theory... got a Lafayette LR800 tube receiver here, that used 7189s. We're about to order Ruby Tubes EL84MRs (basically 6P14s) for it, for a budget rebuild. Should get to test those tubes against normal EL84 and such, as for heater draw (just disconnect the B+ voltage, and test the heater current, with each of the three tubes, 7189, EL84 and 6P14)...
If I can get the tech to do this for me while he's fixing the LR800, I'll do it...
Regards,
Gordon.
It will be interesting to me too. All the sheets I have found, going back all the way to Mullard, show the EL84, 6P14P-EV and the 6P14P to have the same 6.3v, 760mA specs. The Russian sheets are also listing tolerances for heater current, plus or minus 60mA.
It will be nice to know the reality. Thank you for the information and research! You have forgotten more than I will ever know. As in "He spills more than I drink."
Clark in Peoria
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
I should have mentioned for the triode only folks here that pentodes can make truly excellent triodes.
Two of the grids are taken out by wiring them to other tube elements. Usually, one already is. If a circuit is designed for this option, it can be a marriage made in heaven. My Grommes amp has rotary knobs built in for each channel, on the chassis top right next to the tubes, to accomplish the task.
Here is a link to a nice article on the simplicities and complications of the approach, with something to say about EL 84's and EL34's in particular. It is written by a local high end (but sensible) company.
http://www.decware.com/paper16.htm
I think most readers here will find his opinions and observations interesting. It was nice to see efficient speakers equated with "sensible" speakers. Horn guys are going to say "I told you so" about that and an observation about what the ultimate system would be (Steve Schell take note). I think I'm already sorry I posted this...
Clark in Peoria
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
As of 08/09/2006, version 1.1 became available if current users want to update. Handier than a used hankie!
Did you notice the search feature where you can insert parameters and get tube types that will build your design? So cool...
http://http://www.duncanamps.com/tdslpe/
Clark
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
Yeah, but haven't needed it yet. Of course, you've entered your EL84 parameters already, any luck? Maybe some obscure but plentiful substitute?
I really don't know why we worry, 2 or 3 sets of good tubes will likely outlast most of us anyway. Seems like I remember talk of 5-10K hours if biased right, but that was over 10K days ago.
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