• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

EL34 Baby Huey Amplifier

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#1,081
exojam said:
At this point in time is it up to the person wanting to build this to use the schematic in the first post to have their own PCB's made up?

If the first post is not the one containing the most up to date files for schematics, parts etc; could someone be so kind as to point me to the latest and greatest?

Thanks, James
Click to expand...

Hi James,
Member Algar_emi recently concluded a group buy and you may be able to get some PCBs from folks who no longer want to build. See the GB post here:

https://www.diyaudio.com/forums/gro...baby-huey-amp-psu-mk2-pcb-11.html#post6643710

They also have a thread for construction that might me more active than this original thread. The thread is listed in my post.
 
#1,084
SB,

Thank you very much.

Could you please let me know some details about the PCB with regard to thickness, how many layers, trace info, etc.?

I will say up front I have not had a chance to read through this entire thread so if it is already posted you can just say to go back and read, and I would not be offended.

James
 
#1,085
Latest Schematic + Board and some questions

Hi Everyone,
After much reading through the posts, could I ask some newbie questions please. I am in the process of biting the bullet.

1. Which is the most recent correct schematic for the EL34 BH Amplifier
2. Which is most recent board for the above schematic
3. Is there a BOM that is best to use for the amplifier?
4. What do people use for the preamplifier, I understand that there could be a separate preamp, but would adding an EF86 to this be a problem?

I am trying to see if I can build a stereo version for myself?

Thanks,

Earl Josh
 
#1,086
Earl Josh,

If you read this most recent GB you will find the answer to your questions 1, 2 and 3.

https://www.diyaudio.com/forums/group-buys/368190-gb-el34-baby-huey-amp-psu-mk2-pcb.html#post6541976

Re. question 4 - you do not need a preamplifier if your source is a CD player, or similar. You do need a volume control which could be a simple 50K to 100k log attenuator which some folks build directly into their BH amps. And you may need some switching capability if you employ multiple sources.

EF86 has too much gain for a modern preamp, if you decide you need one. Take a Google tour of preamps using 12B4 tubes if you choose a tube preamp.

Good luck.
 
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#1,089
Thank you Francois G,

I will build the amp from there, I suppose 1.6mm PCB thickness with usual thick traces for high current tracks would be the way to go.

Cheers!

Earl Josh

Earl Josh said:
Hi Everyone,
After much reading through the posts, could I ask some newbie questions please. I am in the process of biting the bullet.

1. Which is the most recent correct schematic for the EL34 BH Amplifier
2. Which is most recent board for the above schematic
3. Is there a BOM that is best to use for the amplifier?
4. What do people use for the preamplifier, I understand that there could be a separate preamp, but would adding an EF86 to this be a problem?

I am trying to see if I can build a stereo version for myself?

Thanks,

Earl Josh
Click to expand...
 
#1,092
Well I think if enough people wanted there could be another GB from my understanding (hopefully not talking out of my backside).

I need to contact the gentleman who reached out to me as I have not as out yet to inquire about it.

I am asking for those files since I am just learning KiCad and would like to import them and play around with some component changes and a thicker board. A member over on the Marshall forum made some 2204 boards with .125 inch thick boards and copper is spec'd as 2 oz. He sent one a man is that board stout, along with the pads. That is the kind of board I would like.
 
#1,096
zintolo said:
I don't remember how much they were per pair, but I have three pair of EL34 boards (no psu) and most probably some components as well.

If someone is interested or has an idea of the original price, please PM me.

Thanks
Click to expand...

I've included the BOM, Not mine, but found from somewhere on the site. See earlier GB.
 

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