• 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

Bonjour,

I have build the power supply for the Baby Huey MK2 and during the assembly I found a mistake, hopefully before powering the board :)

The capacitors C1 & C2 are in the wrong direction ! They must be mounted on the opposite direction of the serigraph :eek: I am a little bit surprised that nobody found this error :rolleyes:

I have not yet started the tests because some components are missing, and I put a relay for the picture but I have only 5V version and I need to buy a 12V one...

Bye,
Marc
 

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Francois !!!

I am not always available for tube amplifier support :lifesavr:

I am doing that as a hobby and I am not paid for that ! It take a lot of time for me to write message because I am not a secretary and I am typing with only one finger !! In addition English is not my first language and I make the effort to write in English the best I can but this take time also !!!

I don't want to assume any responsibility because I started a thread, I have designed several PCB's based on the excellent thread from Ian (gingertube) and after the request of many people more than 400 EL34 PCB's and more than 100 EL84 PCB have been sold without profit by Prasi and myself...

Currently, I am busy with others jobs : an Hybrid Amplifier https://www.diyaudio.com/forums/tub...be-amplifier-mosfet-output-2.html#post5840380 and a MPU Ph & Redox Pool Control... I have also made several others PCB's for solid state amplifier and RIAA preampli...

I do my best to answer to builders questions but I cannot be on pressure to make new project on a fixed schedule :no:

Bye,
Marc
 
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Francois !!!

I am not always available for tube amplifier support :lifesavr:

I am doing that as a hobby and I am not paid for that ! It take a lot of time for me to write message

Bye,
Marc

No one asked for amplifier support. I merely wanted to know the status of you new power supply board, which I much prefer over the solution on the previous PCB.

Do you think anyone is paid for this hobby? You had implied a promise to tell us what is going on with your power supply board on June 8th, after many people expressed interest and then you disappeared for several weeks Perhaps not make promises and we will just wait until you are ready.
 
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I bought 4 pairs of the BH boards and after I received them I looked and realized that the design is really not very smart. You tried to optimize for size, but DIY people want to optimize for best sound and ease of construction, with generous capacitor sizes, and a few € extra does matter not much. That is why I am interested in the new boards.
 
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Several people asked for amplifier support and send questions about the EL34 or EL84 Baby Huey and I always answer as fast as I can !

I never make a promise or implied a promise about when I will be back on the power supply board and I have not yet bought the 12 V relay because I am waiting to reach 50€ of order to have a free shipment...

Not so many people have shown interest yet, less than 10 ! As Prasi wrote : He will make a GB if there is enough interest, he made already the 3 last GB for the EL34 & EL84 Baby Huey.

If you don't like the first version of my PCB because you found it too compact, don't expect bigger size from MK2 version because it will be EXACTLY the same size for mechanical compatibility :cool: Why you don't make your own version ?

As I have written several times : I have made these PCB (ECL86, EL34 & EL84 Baby Huey) to test the nice concept of Yves (yvesm) and Ian (gingertube), I made a PCB for me because I am not good for point to point wiring, at the beginning I had no plan to make a GB (I had never made one before) and it's only under the kind pressure of early adopters that I made two GB...

Bye
 
I bought 4 pairs of the BH boards and after I received them I looked and realized that the design is really not very smart. You tried to optimize for size, but DIY people want to optimize for best sound and ease of construction, with generous capacitor sizes, and a few € extra does matter not much. That is why I am interested in the new boards.

Francois, I disagree with your statement that the design is not very smart. I can tell you from experience with my BH el34 that even though the pc board may be compact, the sound is anything but small. There are many progressive circuitry techniques used in this amplifier that IMO contribute to it’s great performance. There are always design compromises. The compact format is an advantage when it comes to fitting all the necessary tube amp parts into a reasonable size chassis. It also allows a simplified and economical construction which is an important consideration for many. As with all DIY tube amps it is an ongoing project with improvements coming with each generation.
I don’t believe the small size limits the sound quality. You can always provide extra filtering for the power supplies or regulation external to the board. The very nature of DIY allows you to customize the basic platform based on your own skill level and preferences. The choice of output transformers, power supply transformers, tubes and capacitors, for instance, allow for a wide range of taste and build cost.
 
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Francois, I disagree with your statement that the design is not very smart.

MARC !!

I owe you an apology and I extend it generously. I meant the PCB design was not smartly done, NOT the design, which was not yours, anyway. I maintain that your PCB was not very well done, why else would you do a new one?

I also explained why I though the PCB was designed with incorrect assumptions, and specifically why I appreciated your new PCB design, which is why I really like your new PCBs and was eager to know more about them.. Somehow you did not appreciate my appreciation of your new contribution, which is exactly why I liked it a lot.

And, to be sure, the implementation of the prior BH design was quite smart. - thT is why I bought several sets of boards. I think you did a good PCB design for the circuit others designed, but with minimal concern for DIY implementation, other than our own. If you are promoting others to do their own PCBs, then please get offer of it first and and do not do your own things!

Answer: Here is where we share! This is. OT where you do your own thing.

Please keep your PCBs for your own use and NOT promote it for others until ypu are willing to share it generously.
 
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Francois, I disagree with your statement that the design is not very smart. I can tell you from experience with my BH el34 that even though the pc board may be compact, the sound is anything but small

Brian, I appreciate your defense of Marc and the BH design. I like that as a new approach to the “old design” paradigm, and supported that by buying several sets of boards for various tube complements.

I apologize that I miss-stated my concern about the “design not being very smart”, as I intended the comment to mean a DIY board which was lacking. The design is not Marc’s anyway; while I liked the design very much. I did not see any innovations in Marc’s boards; just rout implementations in boards, please correct me if wrong.

I stand by the inadequacy of the original PCB, as Marc apparently is too, since he is trying to separate the main board and PSU. My request was MERELY for more information about the new PSA board, which caused Marc’s untimely blowup.

Marc’s response rate to the thread is my main concern - he has been mute for several weeks if not months. If thread starters are not willing to respond to requests for information in say a reasonable 14 days, they should not start threads. Neither should diyAudio accommodate that.

Perhaps Marc is too busy with his new interest, the Simple Mosfet amp, which is fine if there is no implied promise to help people who bought into his BH boards, like me.
 
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Hi Marc,
Have you sent the MKII PCB from schematic at post 478 for production yet?

From Schematic:
R41 and R42 (Bias adjustments) work in opposite directions, you could fix that.
Ideally clockwise adjust should mean increased idle current, that is, decreased -ve bias voltage .

Normally on pots data sheets you see pin 1 and pin 3 at ends, pin 2 is wiper which travels toward pin 3 with clockwise rotation.

If that is the case here, then I think R42 is the correct way round, R41 needs pins 1 and 3 swapped.

Cheers,
Ian
 
Hello Ian,

I am pleased to hear from you after all that time and thanks to give me good suggestion as usual :)

I have not send the PCB files to production yet, I have been quite busy recently and I was expecting some feedback before to produce it... In addition, may be Prasi will make a GB if there is enough interest ? I have made the suggested modification, you will find the schema and the PCB below.

As you have seen, what was just a simple way to build your Baby Huey with a PCB without the mess of a point to point wiring for what I am very bad, has moved in a popular success and all those who have build it love the sound of this amplifier :)

Thanks again for this design and I still expect to build some time the Quad Baby Huey - TENA amplifier (I have already the CFB output transformer) as my ultimate tube amplifier...

Cheers,
Marc
 

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Francois G,

As I already told you, English is not my primary language and I don't understand completely what you are writing :mad:

Let me summaries the facts :

1) I never said that it was my design and Ian helped me to adapt the EL84 Baby Huey to an EL34 version (see post 1729 here : EL84 Amp - Baby Huey and 1752 too) !
2) I have designed a PCB because I am not very good in point to point wiring and the high number of transistors, diodes and resistors make it easier to build with a PCB !!
3) At the beginning I didn't intend to make a GB, that was made after several readers asked for it. That was the first time I made that, it was an interesting but time consuming experience :( Hopefully, later Prasi was kind enough to continue the job :)
4) I wanted to make it in such a way that you need only to add a power supply transformer and the two output transformers to build a complete amplifier, therefor I included all power supply fonctions on board !!!
5) Later, when several people build the amplifier and the interest for the original architecture of the Baby Huey grow up, there was several questions about the possibility to use bigger capacitors, better regulation, higher bias voltage and many people added some external power supply modules, and I was asked if it would be possible to modify the Baby Huey PCB with a dedicated power supply PCB. This was the reason of the MK2 version, not because the first one was a bad design !!!!
6) Finally the power supply board was also a good opportunity to test the power supply of my future Quad KT120 with auto-bias and CFB output transformers and if I follow your last remark I may not publish it if it create so much unpleasant discussion :redhot:

Bye,
Marc