Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: DummyLoad on January 14, 2014, 11:50:16 pm

Title: 6BR7 & 6BS7 pentodes.
Post by: DummyLoad on January 14, 2014, 11:50:16 pm

do any here have any experience with the 6BR7 - a.k.a. CV2135 or 6059? it's small signal 9 pin pentode crafted for AF amplification with U.K. origins.

http://tubedata.milbert.com/sheets/155/6/6BR7.pdf (http://tubedata.milbert.com/sheets/155/6/6BR7.pdf)

i picked up a small stash of them. impressed with the internal construction - looks to be very ridged.

how about the 6BS7? similar specs, but control grid is brought out to a cap. brimar (STC) claims lower input noise with the grid cap design. this one is a 9 pin as well with UK origins.

http://tubedata.milbert.com/sheets/184/6/6BS7.pdf (http://tubedata.milbert.com/sheets/184/6/6BS7.pdf)

can't locate any in the con-us for a decent price. EURO market seems to be to the source for these at this time.

--pete

Title: Re: 6BR7 & 6BS7 pentodes.
Post by: HotBluePlates on January 15, 2014, 06:02:46 pm

Quote from: DummyLoad on January 14, 2014, 11:50:16 pm

do any here have any experience with the 6BR7 - a.k.a. CV2135 or 6059?

No experience with it. But I did notice this tube when I looked through a bunch of data sheets for non-typical tubes that could be good for guitar amps.

You should look up the tube at Frank's (http://www.mif.pg.gda.pl/homepages/frank/)... they've got a 27-page application report for the 6BR7 (http://www.mif.pg.gda.pl/homepages/frank/sheets/184/6/6BR7.pdf).

Title: Re: 6BR7 & 6BS7 pentodes.
Post by: Backwoods Joe on January 15, 2014, 06:07:23 pm

I have used the 6BR7. Much more like the EF86 than the 5879. Very nice, however most of the ones I have used are Brimar brand.

Title: Re: 6BR7 & 6BS7 pentodes.
Post by: PRR on January 15, 2014, 09:55:44 pm

> at Frank's... they've got a 27-page application report for the 6BR7.

Same file. (Milbert is a mirror of Frank's.)

Not fully loading for me though. (Later: loads fine from Frank's; maybe Milbert is having a bad night.)

'Peers to be a funny-made 6J7. 6J7 is a sweet tame tube.

Title: Re: 6BR7 & 6BS7 pentodes.
Post by: zendragon63 on January 15, 2014, 10:11:17 pm

+1 with Backwoods.  I have used a 6BR7--driven with a one section of 12AY7--and thought it sounded pretty sweet for preamp pentode dirt. IIRC, I used the similar values that sluckey uses with the 5879. Different pinout than either EF86 or 5879 though so kind of a pain to directly compare to either.

I am pretty sure nearly all of the 6BR7's were produced by/for Brimar. The two I have are dead quiet; me thinks that you will like this tube. Regards

dennis