Elektor Claus Byrith 4-30

[baudouin0]

Super glad your on the right track - so much for hum loops then. Still surprised at the level of hum there's actually no certainty whether its the EF86 or the ECC83 or both. I've not had this problem even on a guitar pickup.

 

[Kay Pirinha]

Of course. You need to dissipate 0.6 V @ 1 A.
Best regards!

 

[willholmania]

I've got loads of guitar amps and none of them hum like this did - not without a guitar plugged into them anyway. I don't get it either. I don't know whether it's something to do with the power transformer design - no idea. Just glad to be getting somewhere!

 

[Dr Freeman]

hi, willholmania
Please, could you tell me something about this amp? how does it sound, if you like it ...

Thanks

 

[willholmania]

Hi. Yes - it sounds lovely. A really rich, warm, full sound - and pretty tight too. I absolutely love it. I'm thinking of making another and adding an input selector switch and a volume control.

 

[Dr Freeman]

Thanks for the reply. Your amp it's very nice.
Which output transformers did you use?

 

[willholmania]

They're from Primary Windings here in the UK. Whereabouts are you?

 

[Dr Freeman]

I am very glad you like it .
I am also thinking of building it.
Did you have any stability problems with these transformers, since they are not lundahls?
Transformers are probably the most important component in a tube power amp.
Lundahls are very expensive but they are also very very good. What do you think of the hammond 1645A? They cost a little less but perhaps this project deserves the lundahls.
What speakers do you drive?
Sorry for too many questions but before starting a demanding and expensive project it is better to inquire.

Thank you

 

[willholmania]

The Lundahls were too pricey for me and somebody I respect told me the Primary Windings parts would be fine. Maybe the Lundahls would sound better – I don't know, but it sounds excellent as it is so I won't be experimenting. I have no experience of the Hammond parts you mention so can't comment, I'm afraid. I've had no stability problems.

I have a pair of B&W DM2 monitors.

 

[baudouin0]

Very good

 

[astrojet]

nice

Hi. Yes - it sounds lovely. A really rich, warm, full sound - and pretty tight too. I absolutely love it.

Looks great too! Love the aesthetic. Nice job.

 

[willholmania]

Thanks!

 

[Dr Freeman]

willholmania Hi,
Please, can you tell me exactly the models of your output transformer and also the power toroidal?
Thank you very much

 

[willholmania]

Output TXs from Primary Windings.

30W 6600 Ohms Ultra Linear Push Pull Output transformer – Primary Windings

 

[willholmania]

Mains TX

Toroidal Transformer Amplimo - toroidal-transformer.com

 

[willholmania]

Although for my next one I got the mains TX from these guys as they were cheaper. I just gave the the spec of the Amplimo one.

Power transformers - Internet shop Toroidy.pl

 

[Dr Freeman]

Any stability problem with 6.6k instead of 5K? the NFB network it's the same?

 

[Dr Freeman]

Yes Toroidy are spectacular. I've used this in my PP el84. Very very good quality.

 

[willholmania]

No problems at all, except for the hum, which I cured by changing the heater feeds to the EF86s and ECC83s to DC, using a simple bridge rectifier, a large electrolytic and a couple of resistors.

 

[jsantoro]

Can you share the Gerbers?