Dual La2a - [silent:arts] version

[[silent:arts]]

warte auch seit über einer Woche auf ein Angebot welches ich per eMail angefragt hatte. jetzt habe ich gestern halt ein Fax geschickt ...
oder Du rufst Mama Müller direkt an. ist halt ein kleiner Laden

[waldorfcave]

immer anrufen, dann kannst du quasi hören wie dein trafo gewickelt wird

[ChuckD]

Geesh I have to learn German eh.

Nice work !

I have to redesign my front panel now. I like yours better!
Strange to see that the tubes really make that much difference too. Thanks for debugging that for the rest of us. I'll have to look for some Telefunkens as well.


-Chuck

[[silent:arts]]

... I'll have to look for some Telefunkens as well.

some others were good, too. it doesn't need to be "Telefunken".
you can get bad tubes there too.
I hope to have some time doing measuring with different tubes next week at work.
(would like to have a tube tester ...)

[nrgrecording]

Cool. The Hum-anizer from Lothar arrived today.

Time to contact Brian. Or has anyone used other in/out transformers? Hammond, Jensen(man), ...

What about the Neutrik NTM4 1:4 200R/10K... hmm doesn't make much sense because they don't have any usable output transformers.
Die 4 UTCs gingen gestern auch wieder für 230€ bei ebay weg.

Frank.

[[silent:arts]]

I'm planing my next one with Haufe RK310 (600:600) at the Input, and some Edcor (?) 15K:600 for the output.
This LA2As have enough gain, no need for a step up transformer at the Input.

[ChuckD]

Frank,

I am going to be using other transformers on mine simply since I have some already.

Input = UTC A18
Output = UTC A26

On my Drip version I used :

Input = UTC A24 (backwards)
Output = Triad HS-52

I really like the sound of my Drip unit. So I think the Dual LA2A should turn out good with these transformers too.

You are right Volker the LA2A has plenty of gain and doesn't need the step up. Mine I was think of adding +48 volts to the inputs and using it a pre amp too.

==================

Can you explain the grid stoppers you plan to add in rev2.0 in this thread so I can do the same on my 1.0 boards?

Thanks

-Chuck


(kubi) Edit: Corrected login

[[silent:arts]]

Can you explain the grid stoppers you plan to add in rev2.0 in this thread so I can do the same on my 1.0 boards?

Chuck,

as far as I know the grid stoppers are only needed with Sowter Transformers (and only in the too much gain settings).

you can have a look at the subject here:
http://www.prodigy-pro.com/forum/viewtopic.php?t=21907

[bernbrue]

Whow, the finest compression I ever heard. Crazy much gain, this beast. Sowter Input and Edcor output seems fine, first oral tests made me quite optimistic. Sine sweeps show quite good results. More tomorrow. Volker, excellent work. Thx
Bernd

[bernbrue]

Hi,
my 2LA2 is near completion. I use Sowter Inputs and Edcor XSM Outputs. Looking at some RMAA frequency response curves it shows a boost of 3dB in the highs starting from about 3000 Hz. I haven´t terminated the output tx so far. Can anyone recommend any value for the resistor? Should I terminate the primary and/or the secondary side? Here the frequency response.


This compressor is a killer.
regards
Bernd

[[silent:arts]]

I would say the Edcor wants to see 600Ω at the output.

[bernbrue]

This piece of gear rocks, everything is ready to rock, waiting for the faceplate, pictures coming soon .....
Volker, I had a lot of pleasure in building this top of the compressor monster, thx a lot.
regards
Bernd

[crisotop]

Lars,
just a thought. Could it be that you´ve damaged your tubes powering them up without heater voltage?

Is this possible? think I did the same on my drip board with the 12bh7a.

cheers
christoph

[bernbrue]

Hi,
if you got another 12Bh7, I would replace it. When there is an improvent, you know what happend.
regards
Bernd

[crisotop]

I harmed both I've got, will try to get hold of another pair.

thanks for the info,
christoph