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Any EL84 alternatives?

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#5
EL82 looks the same and will drop in the same socket wiring but has lower dissipation ratings. If your amp wasn't asking the most from a EL84 as set up, this could be a possible alternate. 6DY5 and 6CW5 is similar to EL82, also drop-in pin compatible to EL84/6BQ5.

Should try to find 6DIY5's. 😀 (FYI that's an attempt at a joke)
 
#9
At the risk of sounding dense, have you tried different makes of EL84? In my experience there's a wide variance in measured and audible performance, depending on circuit. A JJ doesn't behave like an EH for example. I have to think an OTL headphone amp would make those differences obvious.
 
#10
EL84s sound very different from each other in my EICO HF81 and HF12
B+ is 330, cathode bias.
My experience with tube rolling---

New JJs: Very fat and great lower end, a bit light on the upper end.

New EHs: great sounding all around tube, plenty of bass and good high end.

New Sovtek: These were labled PRO COM and I was told they were the inexpensive Sovtek: Nothing noteable.

NOS Mullards (the real British ones): Exceptional high end and fantastic sound stage, Perfect for acoustic guitar, vocals, woodwinds, strings etc. Much less thump on the bottom end.

NOS RCA: Nice sounding all around tube. Not much kick.

I'm using the EHs all the time but I like many different types of music so they work best for me.

The line stage tubes make a big diffenence in my amp (12au7)
You might experiment there also since they're pretty cheap and you can always use them somewhere.
 
#12
Asides from the originals i had in there (not sure which make they were) i'm using Ei EL84's right now. I didn't notice much of a difference in sound. I noticed a bigger difference when switching the 12au7 with a 12BH7.
The stereo pre-amp has two 12AU7's (BHs now) and four EL84's.
 
#13
The Yugoslavian EL84's I got sound pretty good. 7189's aren't bad, either. I've been working on a Fisher X-101 on and off for the last couple weeks.

See http://www.diyaudio.com/forums/showthread.php?s=&threadid=33049

I put in some 390 ohm resisters for the cathode resistors. The voltage across each 390 ohm resister was 20 V.
V/R = 20/390 = about 50mA of current. 65 mA is typical for class AB1 EL84's. I ordered some 330 ohm resistors. That should be about the right value.
 
#15
I noticed a bigger difference when switching the 12au7 with a 12BH7.
Click to expand...

I would like to try those in my amps. What difference did you notice and did you have to change any resistor values to make the switch??

I ran 12ay7s in mine and with the increased gain it really sounded good but tube cad says resistor changes are required to use them in place of the au7s.
 
#16
ivegotmono,
I went from NOS AU7's to NOS BH7's. I've read somewhere that the BH7's are a more linear tube. And this shows in the sound as being less colored firstly. The AU7 seems to bring out delicates in midrange and highs out while the the BH7 includes teh whole picture with a more sterile attitude--not so much sparke . Not totally sterile though, I would say a very good balance.
I think the 12au7 is good for older classical recordings where there is music in there but its' asking to be sweetened up. Whereas with the BH7 the more refined the recording the more you will be rewarded. Just my thoughts!
 
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