Are EL84 and 6bq5 tubes the same?

[shacky]

I'm borrowing a beautiful Eico HF-81 integrated amp with 6bq5 OP tubes. Just superb. I see a lot of listings state "EL84/6bq5" tubes. Are they the same? Different but similar and interchangeable?

 

[MoparMan]

The same, 6BQ5 is the american equivalent to european EL84...

 

[Dan ʕ•ᴥ•ʔ]

Yup...as are 7189's (military versions)

 

[mhardy6647]

The 7189 is, if you will, a ruggedized EL84; some amplifiers call for the former and will cook the latter quickly (in minutes, for example, in a Radio Shack SAF-40).

 

[Dan ʕ•ᴥ•ʔ]

I restored a Class-A GE console a few years ago that had factory installed 7189's and 7025's (12AX7). I replaced them with Sovtek 12AX7LPS and EL84M's.

 

[mhardy6647]

Both of the Sovtek tubes you just invoked are pretty good (the exception rather than the rule for Sovtek-branded Russian tubes in hifi, I'm afraid).

 

[kvflyer]

Not to be argumentative, but the 7189 is a little better tube than the 6BQ5/EL84. Similar, but a more rugged. The 7189A is a little more robust and the pin out is also a little different than a 7189...

 

[Dan ʕ•ᴥ•ʔ]

That's what we're saying kv.

 

[jaymanaa]

I didn't know that, I thought the A was just controlled warm up. How's the pinout different?

 

[jaymanaa]

Ah, I see, 6 and 9 are tied together internally, but it will still drop in either way right?:scratch2:

 

[analog addict]

Ah, I see, 6 and 9 are tied together internally, but it will still drop in either way right?:scratch2:

Depends on the amp, or so I'm told....:yes: Actually if you believe TDSL, both 6,9 and 1,2 are tied together on the 7189A

On my SC ASR-433, the pins on the sockets are already tied together, so it's a straight drop in.

In fact GE 7189A's sound the best to me on that amp, compared against Mullards, and Bugle Boys....

 

[mpholland]

Interesting thread. I have a little Electra 7189A SE Japanese stereo amp. Haven't checked the voltages on it yet, but have been afraid to drop in my Mullard EL84's because I didn't want to cook them. If I remember correctly the 7189A will tolerate quite a bit more voltage than an EL84.

 

[jaymanaa]

Yes one and two are also connected inside the tube. The only problem I can see, is if the amp used these pins (1 and 6) as "tie points" for something. It would be fine with the 6BQ5, but you would actually be connecting whatever was landed on those, to the grid and screen in the 7189A. This is very good to know.:yes:

 

[pqrannes]

Not to be argumentative, but the 7189 is a little better tube than the 6BQ5/EL84. Similar, but a more rugged. The 7189A is a little more robust and the pin out is also a little different than a 7189...

I know the 7189 are more "rugged" - and can take higher voltage - than ordinary el84s, but it still confuses me that it says el84/7189/6BQ5 on the chassis of my Fisher X-100 while the schematic clearly says "el84" but show that the output tubes have to take 380 V.

If I was to phrase this as a question: will my X-100 work with ordinary el84s (I am presently running it with El84M Sovteks)?

PQR

 

[audiodon]

PQR,
Your Fisher will work with any of those tubes but if you don't use 7189s the life of your output tubes may be shortened. A couple hours or a couple days or even a couple weeks will probably be Ok. But you'll be hunting for tubes in a couple months minimum and a couple of years definitely.
That being said, NOS JAN 6BQ5s are probably close to being ruggedized enough to be considered a 7189.

In my X-100-3, I've experimented with a ton of 6BQ5s, though it calls for 7189s, but I've settled on Sylvania 7189s over the Tele and Ampx 6BQ5s.

 

[roggom]

Have you tried the 6p14p(cyrillic 6n14n) ? I have them in place of the 6bq5 in a maggie amp and rather pleased with the sound and the price.

 

[jaymanaa]

Have you tried the 6p14p(cyrillic 6n14n) ? I have them in place of the 6bq5 in a maggie amp and rather pleased with the sound and the price.

No, but I've been wanting too. This post will give me the needed shove. Thanks, Jay

 

[Tinkerbelle]

No, but I've been wanting too. This post will give me the needed shove. Thanks, Jay

If you do try them, you might want to consider looking at the military versions such as 6P14P-EV (6П14П-EB) (5,000hr) or 6P14P-ER (6П14П-EP) (10,000hr) version for supposed longer life, however they do cost a little more. There's also a -K (see third link below).

The following gives some tech info:
http://mitglied.lycos.de/bk4/tube/6p14per.pdf
http://www.russiantubes.com/prop.php?t=12&p=248
http://www.diyaudio.com/forums/showthread.php?postid=1289959#post1289959

 

[pqrannes]

PQR,
Your Fisher will work with any of those tubes but if you don't use 7189s the life of your output tubes may be shortened. A couple hours or a couple days or even a couple weeks will probably be Ok. But you'll be hunting for tubes in a couple months minimum and a couple of years definitely.
That being said, NOS JAN 6BQ5s are probably close to being ruggedized enough to be considered a 7189.

In my X-100-3, I've experimented with a ton of 6BQ5s, though it calls for 7189s, but I've settled on Sylvania 7189s over the Tele and Ampx 6BQ5s.

Thx for making this clear audiodon657!

PQR