Pour TAD ce sont les Tubes que recommande H&K pour pas mal de leur ampli, notemment le Tube 50.
Pour des questions tu peux les contacter directement.
A l'époque ou je cherchais à retuber mon H&K Tube 50 voilà le type de réponses que j'avais obtenu:
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Moi:
I'd like to buy a matched pair of power tubes: Electro-Harmonix EL34 (Model NN351).
On your website
http://tubeampdoctor.shop-in-worms.net it is apparently not possible to order matched pair of this item but only as single.
Matched seem to be available only for TAD selected tubes.
1) how could I order a matched pair of EL34 EH? What's the price for it?
2) Maybe matched pair of EL34 EH are relabelled TAD after they are selected, in that case which TAD ref should I order? What's the price for it?
For your info I'd like to fit this power tubes in my Hughes & Kettner Tube 50 to get a more Rock and Roll sound, so far I have PM Tubes and it sounds a bit to metallic to me.
TAD:
you can order NN351 EL34EH with standard matching. Just note this in the "COMMENT" field in check-out proceedure.
Please note that we do not recommend this tube for several reasons. One is, that Elextro Harmonix did fail to cover warrantie cases and so we cannot warrantie this tube unless we do offer them as TAD-Premium Selected tubes. We do not offer this EL34EH as TAD Premium tube because the failure for Ig1 is way to high o they cannot meet our quality standard.
For that reason I do highly recommend the TAD-EL34B-STR (order number RT162).
Moi:
I have full trust in TAD’s tubes selection method because TAD is known worldwide for its good work and everybody knows that selecting Tubes is a real know-how.
But TAD-EL34B-STR from which country are they? China (Shuguang, Valve Art), Slovakia (JJ Tesla), Russia (Electro-Harmonix, Sovtek, Svetlana), Yugoslavia (Ei)?
TAD:
thank you for your comment on our QC.
the origin of the tube won't tell you how it does sound. All general pre-judgements are wrong that is what my experience is.
The STR series is designed, tested, selected, matched, printed, labeled and boxed in Germany.
The physical production is in China.
You can find more information about the STR issue in our catalog Products 2004/5 (german/english) which you can download at
www.tubeampdoctor.com
Moi:
Also, what should I order for Pre-amp tubes? Normally we mix different brands of preamp tubes? And how should I place them if there are not all the same (tube 1, tube 2, tube 3 see Service Manual).
TAD:
Preamp: use the RT010 as for input (V1) stage and the RT001 for the other ECC83/12AX7 positions. If (I have no TUBE50 manual on hand) there is a 12AT7/ECC81 required then we prefer the RT002.
Moi:
I don’t think I need 12AT7/ECC81. However tube 3 seems to play a phase inverter role, right? Maybe it’s beyond your technical knowledge.
But so far I’ve been advised to put:
Tube 1:12AX7 EH
Tube 2:12AX7 EH
Tube 3: Chinese Tube like Golden Dragon for instance (probably same type as RT001).
TAD:
I never recommend 12ax7EH as for the same reason as with EL34EH. We have great batches of them and others with 60% reject with hum + crackling noise. Bad part is that the troubles didn't show initially but after several hours working. Again, we stock them but do NOT offerthem selected.
I do recommend to use Va 7025 (RT010) or 7025/E83CC (RT030) and for V2+V3 RT001 or RT003.
RT030 and RT003 have a bit less gain and less clarity which might be good if you play a Tele. If you have hum-buckers then you will prefer the RT010+RT001 as for more details and sparkle.
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Après je leur ai lâcher la grappe et ça c'est fini chez Manulonch.
Vous voyez donc que chacun à son avis sur les lampes. Surtout sur les EL34 EH on entend de tout....