6BM8 tubes... what to use them for!

[Tubenit]

Mini-D

Here are a couple more ideas to toss around. Here are some editable 6BM8 schematics and layout you can edit/change to draw up anything you want. You'll need to have ExpressSCH (which is a free download).

http://www.el34world.com/Forum/index.php?topic=2025.0

http://www.el34world.com/Forum/index.php?topic=3963.0

http://www.el34world.com/Forum/index.php?topic=1890.0

Attached is an idea I've had but haven't built.

With respect, Tubenit

[Alex_SF]

I bid on and won a cool lil Gibson GA-5T amp on Ebay tonight. It is the very early true Skylark model with tremolo. [...] Problem now is finding a schematic, as Gibson was known for changing up schematics from year to year. I can find the SE 6V6 model, but have yet to come across the SE 6BM8.

Nate -- Don't know if you're still looking for this schematic, but here it is. I scanned the one that came with the GA-5T that I have. (Scotch-tape repair of a tear through the voltage chart may be apparent but it's still legible.)

Anyone know which resistor I should change to try and get a deeper tremolo effect out of this amp? It looks like it might be either the 510K or the 1.5M resistors connected to the switch, but I'm not sure.

I'm considering doing a build to make a head based on this schematic, but with parallel single-ended 6BM8s in the output stage for ~ 8 watts like an old Gibsonette. Only question is what to do, if anything, with the unused triode stage in the additional output tube. Extra gain stage perhaps?

[Tubenit]

GA-5T schematic and layout

Here is an editable SCH version of the GA-5T schematic and layout (but you will need the free download SCH program).

http://www.el34world.com/Forum/index.php?topic=3783.0

Check it for accuracy with the other schematic that was posted.

Tubenit

[ETR]

I'd probably use them for nitelites.

[Tubenit]

6BM8 tube amp

Not sure why you'd use 6BM8 tubes as a nite light?

Here are sound bits of a 6BM8 Little Wing amp that sounds incredibly good to me:

http://www.musicwebtown.com/jallenshaw/46763

I have not heard very many amps that sounded any better to me.

With respect, Tubenit

[Wrongdog]

Yup, sounds great. The player has tone too though. I love the compression yet still very touch sensitive. What was the set up?

[Le Basseur]

Here are sound bits of a 6BM8 Little Wing amp

Nice tones,even nicer playing,I really enjoyed the blues "as is" and,on the other hand,the "Al di Meola-wannabe" Hot Potato!Congrats!

[Tubenit]

Little Wing (6BM8 mini-Bassman)

I guy with a handle of DaGeezer came up with this amp. If you have the free download of ExpressSCH, there is a schematic and layout here:

http://www.el34world.com/Forum/index.php?topic=562.0

I did reverb version of the amp but changed some things on it.

With respect, Tubenit

[imaradiostar]

Here's a link to my 6bm8 project. It's a cascode front end into a Dr Z style tone section and ac15ish 6bm8 output. I inserted verb in a similar manner to the other projects on the el34world forums.

Sounds pretty good, not as pleasing to the ear as a real pentode though. There is still some room for experimentation though!

jamie

[Alf]

Jamie ,

Did you forget to link ?

I'm very interested in these kinds of lowpower amps.
And could you give some more informationa baout the type of caps you used.

Coupling , decoupling and ps caps.

Alf

[tboy]

Here's a link to my 6bm8 project.

I think you forgot to insert the link.

[imaradiostar]

I think you forgot to insert the link.

Hahah! Yeah, I forgot the link!

http://www.el34world.com/Forum/index.php?topic=5736.0

Try that one...

In all fairness I think the little wing reverb idea would probably be more versatile. I'm going to build one of them soon for a friend, probably with 6aq5 outputs instead of 6bm8 since I have a bunch of 6005w's that I bought on ebay.

I'm going to try to record some sound clips of my 6bm8 amp- seems like it might be a good amp for pedal usage on smaller gigs when I can only use one amp. I may even wire an additional socket so I can swap a pentode in when the mood strikes.

jamie

[imaradiostar]

I was reading last night that the British made 6bm8/ECL82 tubes are mechanically similar to a KT66 but obviously smaller. Supposedly they were trying to take advantage of the hifi success of the KT66 and make a tube with similar characteristics for low power audio use. Can anyone verify this?

I'm hoping that this tube will achieve a similar sound in an 8-10 watt push-pull amp.

jamie

[capnjuan]

Hi Jamie; two links to push/pull 6BM8 amps; Gibson GA8T (tweed) and Univox U45B. Good luck with your project. CJ

http://www.schematicheaven.com/gibsonamps/ga8t.pdf
http://www.schematicheaven.com/barga...nivox_u45b.pdf

[chris shaw]

hi tubenit
I love th tone of the link you sent but cant find the schematic, or indeed references th dageezer little wing
DO you have apecific link
I am new2 to this game having just built an ab763 deluxe reverb which is just too loud for my gigs
I think this woiuld be a perfect replacement but need schematic and layout
thanks
chris