Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on October 29, 2023, 04:20:20 pm

Title: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: kagliostro on October 29, 2023, 04:20:20 pm

Today in the wake of TIMBO who has his hands on a stereo circuit with 6BM8

at a local Flea Market I recovered a Stereo 1965/67 Telefunken Musikus 5062 Turntable Phono Suitcase

Tubes are 1 x ecc83 and 2 x ECL82 (6BM8)

(https://i.imgur.com/oB8gQG3.jpg)

(https://i.imgur.com/4ddJKvD.jpg)

My idea is to maintain the original PCB

take off all the components (maintaining tubes) and mount on it components to obtain a Stereo 2 x 5F2A or AA764 (for the TS, without vibrato)

Any thought about how to have two different channels ?

Thanks

Franco

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: kagliostro on November 03, 2023, 04:52:14 pm

Based on the Champ AA764

(https://i.imgur.com/dGrWIcs.jpg)

And wanting to have two different channels I've think to this

(https://i.imgur.com/TKIBDio.png)

What do you think about ?

Any consideretion and/or council wellcome

Thanks

Franco

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: TIMBO on November 04, 2023, 02:14:37 am

Hi Franco,
That looks good.
There is an option to add a third input jack that will parallel the two channels
Possibly keep the Tone controls of one channel as stock for simplicity and uniqueness.
Stick a speaker driven reverb between channels
Happy dayz....

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: kagliostro on November 04, 2023, 06:02:53 pm

Ciao TIMBO, Thanks

Quote

Possibly keep the Tone controls of one channel as stock for simplicity and uniqueness.

Do you mean to don't swap the 10K middle resistor of one TS with a 10K middle pot or what else ?

Franco

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: TIMBO on November 04, 2023, 07:13:58 pm

Hey mate, I meant to keep one of the stereo's channel stock, it might have some MOJO to it

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: kagliostro on November 04, 2023, 07:26:35 pm

Ah, OK, I misunderstanded

Thanks Again

Franco

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: kagliostro on November 05, 2023, 04:39:03 pm

I'm seriously thinking to follow your council TIMBO

May be I'll modify the circuit only around V1 as to guitarize it and maintain all the other as stock


Franco

Title: Re: 6BM8 Telefunken Stereo amp recovered - May be a 2 x 5F2A - Seeking for ideas
Post by: ALBATROS1234 on November 06, 2023, 04:14:14 pm

I converted a M8 stereo reel to reel which had two single ended amps. I made one side and EL84 champ and the other side a vox AC4. Turned out quite nice and he could play either or use an A/B switch and go stereo