EL84 Amp - Baby Huey

[zintolo]

Current feedback, even if very low. I remember an old pdf saying there was an optimum for EL34 (and so others as well), but I forgot.
I usually keep 1 Ohm to ground on output tubes.

 

[tnvijay]

The amplifier has been completed and it works extremely well.. Changes from the original schematic includes Individual bias pot provided for all tubes ( to get equal current draw). The coupling cap was changed to 400 v ,0.43 MFD, metalised polypropylene..

 

[zintolo]

That's great! Pleased you like it.
You search differences to which schematic? Boards already have individual bias pots.

 

[tnvijay]

I did the Yvesm original schematic with Pcl86, no PCB,But point to point.. Individual bias pots and the current draw resistor in the Cathode are the differences from the original schema, and not to forget, Potentiometer is 22k linear.. ( log pot not suitable for my liking)

 

[tnvijay]

A rough image. still needs final wiring alignments and cleaner looks

 

[elac310]

Omg! 136 pages to go through to get all the details: what OT primary, what PT ht voltage and power, input sensitivity for which power etc

I take it that the schematic numbered “8” in the first post is the final (does any such thing exist on DIY) schematic that can be trusted etc.

Could someone kind and empathetic enough tell me in 2-3 sentences why this schematic is so nice/ works so well, besides its apparent simplicity ?

 

[elac310]

Reason is I’m planning such an amp.

 

[zintolo]

That configuration triodifies the curves of the output tubes, giving linearity and damping at the expense of the phase splitter load.

 

[Francois G]

I take it that the schematic numbered “8” in the first post is the final (does any such thing exist on DIY) schematic that can be trusted etc.

Not sure which schematic “8” you are referring to. Attached is the final version of the “official” schematic for the Baby Huey EL84 version that I have. There were a few minor changes - Zintolo, do you still have your list of changes to the EL84?

 

[zintolo]

I did a thread about them (including some preferences of mine): https://www.diyaudio.com/community/threads/slowly-building-three-baby-huey-el84-with-notes.358831/

 

[tnvijay]

And here is the final outcome.

 

[jazzzman]

tnvij, your build looks great. From where did you obtain the vu meters?

 

[tnvijay]

Jazzman, Thanks! I got these VU meters from theaudiocrafts.com,an online electronic spare shop from India. It is the Nissei TR 35 VU Meter and it is widely available across many online sources

 

[jazzzman]

Thank you!

 

[ilorev]

Sarà il caldo ci metto molta pazienza ed ecco un lay6 di BW.
È necessario un sopralluogo da parte vostra. Dimmi errori poi le gerbere saranno a disposizione un ricordo al grande Marc... RIP
il lavoro è attualmente non testato

 

[snapper]

If I look at it like that, I would say at first glance that you should better leave it
Forum language should be English, then the next one starts with Kisuaheli?

 

[zintolo]

Ilorev wrote:

“It could be the heat, but I have to put a lot of patience. Here's a lay6 of BW.

An inspection is required on your part to look for mistakes, as the work is currently untested.

Gerbers will be available as a keepsake to the great Marc... RIP”

 

[ilorev]

Hi
my second language is French...for English I use a translator ...Patience...copy paste wrong.

 

[anatech]

Hi ilorev,
Well, most speak English. Why have everyone else translate?

Sarà il caldo ci metto molta pazienza ed ecco un lay6 di BW.
È necessario un sopralluogo da parte vostra. Dimmi errori poi le gerbere saranno a disposizione un ricordo al grande Marc... RIP
il lavoro è attualmente non testato

Through a translator gives us :

It will be the heat I'll put a lot of patience and here's a lay6 of BW.
An inspection is required on your part. Tell me mistakes then the gerberas will be available as a keepsake to the great Marc... RIP
the work is currently untested

-Chris

 

[snapper]

hello, i finally managed to insert the component values into my copy,
9pin pcb noval sockets and the adjustable potentiometers are now on the other side!