Is it necessary to make the "checkout" after I have made a replacement of the output transformers in the Tse?
I Want to make a change from Lundahl Ll1620 to Ll1620-am output transformer? Or is it OK just to make the replacement?
I Want to make a change from Lundahl Ll1620 to Ll1620-am output transformer? Or is it OK just to make the replacement?
If the OPT's have the same DCR the swap should not change anything. Fiddling around inside the amp could bump something, so at least checking the idle current would be a good idea.
I checked mine every month or so in the first year since I had used some tubes that were about 75 years old at the time. Now at 90 years old they haven't changed in a long time. I still check them every few months or whenever the amp hasn't been used in a long time.
I checked mine every month or so in the first year since I had used some tubes that were about 75 years old at the time. Now at 90 years old they haven't changed in a long time. I still check them every few months or whenever the amp hasn't been used in a long time.
Thanks for the feedback George. The DCR is the same for the Lundahl iron and Amorphous type, so it seams to be easy to change to AM.
The Opt's from Lundahl have a switch option from 16 to 8 or 8 to 4 ohm impedance by a switch in a little board, so that is easy to switch from 8 to 4 ohm impedance. I think it is nice and a God idea. I am super happy with the Tupelab SE and the Lundahl OPT's. And 45 tube's from emissionlabs. It is a eery God combination and fantastic sound. You'r SE driver board George deserves the absolute best... I can't imagine a better amplifier.
The Opt's from Lundahl have a switch option from 16 to 8 or 8 to 4 ohm impedance by a switch in a little board, so that is easy to switch from 8 to 4 ohm impedance. I think it is nice and a God idea. I am super happy with the Tupelab SE and the Lundahl OPT's. And 45 tube's from emissionlabs. It is a eery God combination and fantastic sound. You'r SE driver board George deserves the absolute best... I can't imagine a better amplifier.
Hej George + tubelab forum.
Jeg har et spørgsmål om check-out på min TSE II. Jeg har et problem. Det er ok indtil jeg sætter udgangsrørene ind og prøver at åbne op for bias til 25 mA.
Der sker ikke noget... Spændingsfaldet en lille smule fra -219v til -195v, men mA over R18 og R29 er stadig 0. Der er ingen reaktion når jeg åbner op for R12 and R23
Varmespændingen er ok, and the - 175v på 5842 er ok, B+ er 345v
Jeg har prøvet med forskellige par fine ok 45 rør, men det samme sker. Det er ikke muligt at justere nogle bias flow. OPT'erne er korrekt installeret. Hvad kan det være?
Med venlig hilsen
Michael
Jeg har et spørgsmål om check-out på min TSE II. Jeg har et problem. Det er ok indtil jeg sætter udgangsrørene ind og prøver at åbne op for bias til 25 mA.
Der sker ikke noget... Spændingsfaldet en lille smule fra -219v til -195v, men mA over R18 og R29 er stadig 0. Der er ingen reaktion når jeg åbner op for R12 and R23
Varmespændingen er ok, and the - 175v på 5842 er ok, B+ er 345v
Jeg har prøvet med forskellige par fine ok 45 rør, men det samme sker. Det er ikke muligt at justere nogle bias flow. OPT'erne er korrekt installeret. Hvad kan det være?
Med venlig hilsen
Michael
To save time, here's the translation.
Hi George + tubelab forum.
I have a question about check-out on my TSE II. I have a problem. It's ok until I put the output tubes in and try to open up the bias to 25mA.
Nothing happens... The voltage drop a little bit from -219v to -195v, but the mA across R18 and R29 is still 0. There is no response when I open up R12 and R23
The heating voltage is ok, and the - 175v on the 5842 is ok, B+ is 345v
I have tried with different pairs of fine ok 45 tubes, but the same thing happens. It is not possible to adjust some bias flow. The OPTs are correctly installed. What could it be?
Yours sincerely
Michael
Hi George + tubelab forum.
I have a question about check-out on my TSE II. I have a problem. It's ok until I put the output tubes in and try to open up the bias to 25mA.
Nothing happens... The voltage drop a little bit from -219v to -195v, but the mA across R18 and R29 is still 0. There is no response when I open up R12 and R23
The heating voltage is ok, and the - 175v on the 5842 is ok, B+ is 345v
I have tried with different pairs of fine ok 45 tubes, but the same thing happens. It is not possible to adjust some bias flow. The OPTs are correctly installed. What could it be?
Yours sincerely
Michael
It is so tight in there, is this one of those jobs where you have to go backwards before you can go forwards? I.e. get all the constituent parts on a desk and treat it as the initial setup?
Some of the old coil-rich tube circuitry with chokes and transformers packed cheek to jowl and yet dead silent is really impressive. Looking at one Telefunken receiver in particular years ago I expressed my admiration to an engineer who said "Yeah, back in those days they had the resources (ie. time and manpower) to have a tribe of lab engineers and techs trying every layout possible until they hit the magic."
Getting your transformers tight together like that without any hum is a good job! Nice!
Getting your transformers tight together like that without any hum is a good job! Nice!
There is definitely no hum. In the first check-out I hear a little bit hum, then I changed the power transformer from Hammond 370 EX to the bigger 370 HX and it makes an important difference. It seems to have had a beneficial influence on the build. Luckily...
