|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
209.95.50.67
In Reply to: RE: What tube subs for a 6BL8 posted by DAK on October 01, 2015 at 13:46:37
DAK,
Here is a chart of the tubes interchangeable with the 6BL8:
6GH8, 6U8, 6BL8, 6EA8 ratings
Tube....Pentode Trans.....Power...Triode Trans....Power
6GH8.....8500 umhos......2.5W......7500 umhos....2.5W
6U8......7500 umhos......2.5W......5000 umhos....3W
6BL8.....5000 umhos......1.5W......6200 umhos....1.7W
6EA8.....6400 umhos..... 3.1W..... 8500 umhos....2.5W
The 6GH8 has the highest output and was common as a television tube and is said to be found as low quality when marked as a TV brand.
I have a McIntosh MR67 tube tuner that uses a a pair of 6BL8's a s a "pre-preamp" output tube and the sound is fantastic. The 6BL8 European designation is ECF80 and there are premium version E80CF and military version 7643. Ten years ago , since none of these types were in production, I decided to try a few. As they were inexpensive,- some were $2 or so, I ended up with:
6BL8 /ECF80 /E80CF /7643
2- Telefunken E80CF- gp- NOS -
4- Philips Miniwatt ECF80-- Brazil- NOS -
4- Valvo E80CF Red lbl, pinch waist- gp-DE- NOS
2- Philips SQ E80CF - Germany, gp-USED-TNOS -
4- Philips SQ / Mullard- E80CF- disc gtr- UK- NOS
3- Siemens by Telefunken 7643- s.gtr - gp- DE- NOS
3- Amperex PQ E80CF-gp-Hamburg-db.gtr-NOS 64-
5- Siemens & H by Telefunken E80CF- gp- - NOS
4- Amperex PQ 7643- gp- Hamburg- db.gtr s- NOS
4- GE ECF80 -UK - NOS
2- RCA 6BL8- US - NOS
3- RCA ECF80 -France- NOS
1- Sylvania 6BL8- US
It turned out that were really two basic kinds, the Philips / Amperex / Mullard have two substantial triangular getter supports and the Telefunken / Simens design looks more like a conventional triode. I found I much preferred the sound of the Philips design and use a pair of Valvo E80CF pinch waist, gold pin in the MR67, but the ordinary while label Valvo Amperex are all fine. Very low microphonics and a great soundstage. I used to listen to the MR67 in mono and the sound was just astounding and even imaging was incredible- narrow, but deep, deep deep suggesting very good phase coherence.
I liked the sound of 6BL8's so much I looked to see if there had been any preamps that used them as a gain tube.
Cheers
Bambi B
Oracle II_SME V_AQ 200 / MCintosh MR67 /Cambridge Audio 640C v2 > Audio Research SP10 > Audio Research D115 > Vandersteen 2C (AQ King Cobra IC / AQ Rocket 88 speaker)
Follow Ups:
Hi Bambi, that is great info. Actually, I found your original post on another site and have it bookmarked for future reference. Now, I all I need to do is find where I put those danged E80CF tubes. I know I put them in a little box, I just hope I labeled the outside of the box. cheers, Dak
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: