I clonning Milbert BAM230/235 Car Tube Amplifier Supply

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Hi Travis,
just saw your post about your Milbert 235, im curious of its inner workings, not to copy, im working on (3) Mobile tube amps of my own, they will be much more power than the milbert, lowest power one im working on is 45wpc, going to build a 2 and 3 channel along with a mono block one, 1st mono one im hoping for 120W, depending on how my power supply works out, if its stable with power to spare (and it should), ill have to get a OPT made and would like to get it to 275W on the mono block. ill keep you posted, and will post pics when we get there.. John
 
mobile Tube Amplifier

Hi fellas,
I realize as well this is a kinda old post, but i am working on 3 mobile tube amplifiers that should make more power, and use more common power tubes like EL34,6l6, kt66 kt88 and im going to build a mono Subwoofer amplifier that can use most octal socket tubes, bias will be cathode bias but not fixed bias, they will be adjustable with sockets to plug in a VOM on Ma scale and set bias. this amp will at first employ 6550's, once i know my power supply robust and stable, a PPP version will be coming, dont worry, i will post plenty of pictures..
 
i was going to ask what tubes it uses, but i found a thread that had a inside picture and tube it uses listed, it may have been yours? till i found the picture i have NEVER see the inside of one, and funny thing is, i didnt even know Milbert existed till a did a internet search one day wondering if anyone has ever done this other than Butler Audio which i have owned 1 before, and there only tube front end, transistor power hybrid, However, probably one of the best quality amplifiers ive ever seen on the inside, they T 03 power transistors that are in sockets, components that you would see in a military piece of electronics, its designed to be serviced if need be.
 
Hi JAW (John) - I'm not sure which pics you found. I have some pics as I disassembled the Milbert BaM230 and reverse-engineered a good portion of it.

Yes, Milbert's amps are very rare and very old, dating back to somewhere around 1986, if you can believe it. (Mine had a copyright date on the PCBs from 1986).

The Milbert isn't hard to service either, for most sections like tubes.

FYI, for whatever amp you're using, you can just take a DC-DC 12V supply (isolated) and invert a step-up supply for the negative grid voltage to make that part easy.

That's what I did: 12V-12V DC isolated -> Inverted 12V - 200V step-up supply = -200V grid voltage.

If whichever power supply you use isn't isolated, you'll have "ground loop" noise. The Milbert didn't have a modern front-end design so it was isolated.

For my project I took "ground breaking" input example from an Alpine schematic to deal with the ground noise problem as mine was not an isolated main SMPS (not very practical to do).
 
If anyone else is still interested in this subject, post here or PM me.

I just got extremely lucky and got a BAM-235 last week!

It would be great to sort out the design, document it (especially the transformers), and be able to duplicate it. The design is not particularly intricate but the switching power supply details are the critical issue, I think.

hello Do You have some diagrams ? i Would love to make a copy of bam 230 or 235 just need some specs :)
I would be very grateful
 
Hi Travis,

I found an old post where you mention that you have a Milbert bam235 manual in pdf form?

I would like to change the tubes in my amplifier, but I do not have my manual and tube bias instructions, and I am hoping that I can impose on you to email a copy of your to me?

I’d greatly appreciate it if you would :)

My email is: peterlufrano@comcast.net

Thank you so much in advance!
On the Milbert site can find that you need.
 
Наверно забанили,а схемку от bam 230 или 235 хорошо бы скачать,ТАК И НЕТ?

Probably banned, but it would be nice to download a schematic diagram from bam 230 or 235, SO NO?
:cop: Please add an english translation if you post a non english comment.

:cop: Пожалуйста, добавьте английский перевод, если вы публикуете не-английский комментарий.
 
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