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I would like to remove the annoying chat at the bottom. How ?

What is the blueprint for manufactoring a certain tube ? Is there an "owner" that has blueprints for the components ? And if so, is there any licensing or patent issues ? Or is the creation av a new instance of a tube a matter of combining and dimensions of the elements so that the end results...

Starting out as a comment from a friend many years ago i was curious on the Dynaco PAS4. No such preamp ever came to sweden, few was build and most stayed in US. Some years ago Roy Mottram announced that he would build a few clone boards, i bought one. Finally i got to build it. And i am amazed...

To all of you i wish a very good xmas.

Looking at the MkVI schematics ( no i do not have any) i see a feature that seems strange. Dynaco has introduced a time relay on the B+ feeding the driver tube, a 7199. This implicates that when the powertubes are hot and drawing current a sudden positive surge will occur when the timerelay...

I have been connected by a user of this amp, anyone that has a schematic or information in any other language then french ?

Yet Another Dynaco REBuild It might be of broader interest; i badly wanted a remote volume, and i also needed a buffered output to my PAS-3. The end result was a quad buffer with remote control and in addition a power sequencer / protector for the power amp. See...

Is it the lead-free solder that makes it hard to get decent solders ? Lot's of problems seem to be related to "bad soldering" or "cracking solders" This was not the typical problems kit builders or doit-yourself builder experienced in the 80's, the period i was most active.

Last april i bought 3 7199 from mullard magic. They were advertized as NOS. It's also what staed on the reciept. (NOS for me is New Old Stock). Some weeks ago i had the opportunity to measure them with a tube tracer, and they were far from new. They were in fact at the very limit of useless...

I could not resist building a uTracer ( dos4ever.com) as it seemed to be a nice design and does have the ability to not only measure but also make tube graphs. The first samples are measured with the gear on my table, now it's time to mount in boxes. uTracer uses a u-controller to pulse the...

According to "Computer sweden" Sylvania has taken over ericssons phone factory in Ronneby sweden, and plans are for producing a number of the most profitable tubes. 7199 and 6550A is two of the initial products, with more to follow. See "http://www.lurad-i-en-burk.se/torsk"

I have ( as usual ) stumbled into an area where i did not know what i was talking about. (big mouth opens too fast for brain to catch up-syndrome :-) There is apperently some sort of auto-bias in mcintosh amps such as mc275 The schematic is available but frankly i do not understand how...

If i should start selling tubes i'd need to supply matched pairs ( or quads) Whats the definition of "matched pair" ? Is it "simular current at some voltage and bias" ? ( which voltage ? A typical for the tube ( 400V for EL34, 500V for 6550 ?) Or is it simular current and transkonductance...

As my mentor and friend from many years has moved to another world i need to broaden my views. I've done transistors, and each time i'm back into tubes. The latest is a vta-70 that sounds very nice. My audio-interest is a hobby, although i am thinking of redistributing jj in europe ( why...