• 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.

I completed my amp!

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I just completed my new 300B SET amplifier! After months passed searching for the components and building the cabinets, I finally warmed the solder! Infinite THANKS to my friend Derek Walton for his precious aid! and also to Joseph Esmilla for his fantastic scheme that we used as starting point. It sounds marvellous to my ears!!
Ciao a tutti
Vincenzo
http://homepage.mac.com/parisatnight/hobby/PhotoAlbum2.html
An externally hosted image should be here but it was not working when we last tested it.
 
Thanks for posting your amp and the link to your homepage. I am in the beginning stages of my first DIY tube job (just started drilling holes last night). Seeing real craftsmanship like your amp exhibits gives me much needed encouragement. Will any quality brand (Mars, GE, etc.) oil filled motor run cap do nicely, or are there certain types or brands to look for. I saw some on E-Pay that touted non-magnetic terminals. I just wandered if I need to be aware of any to stay away from. Thanks again and beautiful work, Jay

P.S. I don't think I'm ready to try those dove-tails just yet, but maybe on the next:smash:
 
ttan98 said:
I don't want to sound negative, the B+ @ 425VDC on the 300B is too much I believe that will reduce the the reliability of this EXPENSIVE tube....At this voltage you will only gain 1-2 watts extra...

Really? I have a set of Welborne 300B amps, and he has the B+ set at 550V, and he calls these the low volt version. I think 425V is fine for 300B's. In fact, I use cheap valve art tubes that have a lower than normal plate dissipation, and they have been fine for the better part of a year.
 
Geek said:
Nice work! :)

How on earth do you get the dovetails right? I have a dovetail bit for my router and always manage to scew it up :(


Completely handmade! ;)


Giaime said:
Ciao Vincenzo!!!

Can you tell me where you get the transformers, tubes, those big cromed capacitors, etc?

Thank you very much!


Ciao! In Italia RS Components has the whole Allied catalogue, so you can have in a few days the ASC capacitors that I used. You can also find them at Olimpia Audio...

PTX is handmade by Novarria and OTX and choke came from Tubetown, in Germany..


ttan98 said:
beautiful amp!!!!

I don't want to sound negative, the B+ @ 425VDC on the 300B is too much I believe that will reduce the the reliability of this EXPENSIVE tube....At this voltage you will only gain 1-2 watts extra...


B+ voltage - cathode voltage = plate voltage!

Thanks to all for the kind words!! Ciao :cool:
 
Ciao! In Italia RS Components has the whole Allied catalogue, so you can have in a few days the ASC capacitors that I used. You can also find them at Olimpia Audio...

PTX is handmade by Novarria and OTX and choke came from Tubetown, in Germany..
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Thank you! Yes I know Silvano from Olimpia Audio very well ;)

Why OTX from Tubetown and not from Novarria? Have you ever tried OTXs from Novarria? And what about the PTX, how are they?
 
Merlinb said:
That's a fantastic looking amp!
Few questions:
Why did you use rubber grommets on the valve sockets?
Why did you use carbon resistors and not metal films?
Did you put a base-plate on or is it permenantly 'open' underneath?


300Bs are narmally quite microphonic. Grommets aid to insulate the tube mechanically from the cabinet.

I prefer the sound of carbon resistor. I selected each pair of res from a lot of ten in order to match the values.

I use a silver ground buss, the top plate is connected to it only in a point: a screw near the first cap after the choke.


Giaime said:


Thank you! Yes I know Silvano from Olimpia Audio very well ;)

Why OTX from Tubetown and not from Novarria? Have you ever tried OTXs from Novarria? And what about the PTX, how are they?

Because I knew the quality of the Hammonds (volevo andare sul sicuro) and also because they have a stunning quality/price ratio... But I know a friend of mine that built the same amps with custom Novarria "C" cored OTX with great results!

Ciao
 
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