Davoli Or.ba.ch. b6 replacement tubes

Started by wootzy, February 26, 2010, 04:15:59 AM

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wootzy

Hi,

I've a old Davoli Or.ba.ch b6 amp which could use a tube refresh.
The issue is that I'm having trouble identifying the tubes and don't know at what a should pay attention while picking up replacement tubes.

The amp has a total of 4 tubes, 2 big ones and 2 small ones (all have 9 pins).
The big ones have "Adzam EL 504" printed on them and I think can be replaced by http://thetubestore.com/nos-6gb5.html/.
The smaller ones however, I have difficulties identifying, they have "6189 FEC-7102-FF made in France" printed on them.

Any help would be greatly appreciated.
Cheers

MCK-fgn

#1
I think the smaller ones are your preamp tubes and the 6189 seems to be an equivalent to 12AU7 which is generally a lower gain version on the venerable 12AX7. See the following for a potential replacement.

http://www.tubedepot.com/nos-6189.html

Your power tubes are a little harder to track. I think the EL504 is similar to EL500 which is listed as equivalent to 6GB5 for which I was able to locate some sources on the net.

If you wish I can post this query for you on the www.ampgarage.com where there are many tube amp gurus. Might take a few days to get more insight.

Hope this helps.
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Elantric-fgn

. . . the future ain't what it used to be . . .

wootzy

Thanks for the feedback MCK!

Would greatly appreciate it if you could find out more about theses tubes.

Pics attached.

Thanks!

Elantric-fgn

#4
EL-504 specs here:
http://tdsl.duncanamps.com/dcigna/tubes/sheets/pl504.html

It can be replaced with a 6GB5

http://thetubestore.com/nos-6gb5.html

6189 is like a 12AU7 - insert a 12AX7 will make it have more gain/distortion
http://www.vacuumtubes.com/12au7.html
   Both of these are "milspec" versions of the 12AU7.  They may also be marked with 12AU7WA.  They both have thick mica wafers which give the tube extra rigidity which minimizes any microphonic problems.  Their cathodes have been specially designed so they can withstand many on/off cycles and long periods in cut-off without any degradation of performance.  The 5814 has a slightly higher filament current demand than the 6189/12AU7.  Some (not all) Sylvania Gold Brand versions of these tubes have gold plated pins.


Athos Davoli spa is still alive in Parma(italy)  - i visited Parma in 2001 when I was working with Parsek Markbass/EB HD-500

I love the Adriatic coast!

http://parma.paginegialle.it/emilia_romagna/parma/strumenti_musicali_e_accessori.html
MUSIC CENTER DAVOLI
di DAVOLI ATHOS & C.

43122 Parma (PR)

3, v. Tartini

tel: 0521 270510

fax:0521 270970


. . . the future ain't what it used to be . . .

wootzy

Wow ... thanks for the excellent info!

Found the tubes on e-bay, hope I can restore this amp.
Eager to find out how it will sound with the RIP and G4.

Still  need to figure out witch speaker(s) I can/should hook up to this amp.

Thanks Elantric!


Elantric-fgn

#6
Looks like you are set for 8 ohms at present:

Look over on the right - thats the Output impedance Select Strip -

It produces about 5 watts RMS



. . . the future ain't what it used to be . . .

matbard-fgn

Quote from:  Elantric on February 26, 2010, 10:08:01 AM
I visited Parma in 2001 when I was working with Parsek Markbass/EB HD-500
Steve,
What do you think about the Markbass bass amps?
-

--> Matteo Barducci

Elantric-fgn

Re MarkBass. They produce wonderful products, highly recommended.
. . . the future ain't what it used to be . . .