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Old 29th September 2012, 09:23 PM   #401
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Join Date: Oct 2006
Location: Karalee, Queensland
Morten, the journey to audio heaven sounds like it is over. There will be lots of unwanted Tram2 tubes on ebay from this. One way to recoup for the cost of the Full Music tubes. All the best

Peter
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Old 30th September 2012, 09:51 AM   #402
Desmo is offline Desmo  Denmark
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I'm not buying more 45's or 2A3's for sure So I a bunch of tubes collecting dust... I have a pair of EH 2A3 (cheap ones just to get started). Two pairs of NOS RCA 2A3. The Treasure 2A3 and a pair of NOS Sylvania 45's.

The NOS RCA 2A3 might be the ones that come closest to the Full Music 2A3/SE. The have some of the same sonic footprint, or maybe I should say some of the same LACK of sonic footprint. They do not sound as good though, and what has kept me from using them more is, that there are all kinds of problems with them: With one pair there is hum, I could reduce this by making shielded tubes / housings for the tubes, but I don't want that. The second pair is extremely microphonic. Too bad because they sound quite good, but ultimately they are not for preamp use (IMHO). For a power amp I'm sure that they will work much better...

Anyway, with the Full Music 2A3/SE there is no need to consider tubes for a while And with the soft start of the heaters from the Rod Coleman regulators and the intelligent start up from the autobias module in the Tram II tube life should be up to 2000 - 5000 hours for a pair of these tubes, so the investment is not too bad - per hour.

I will play a bit with rectifiers and mu tubes again. For now I use NOS RCA rectifier and a NOS Cunningham 6AS7. This combination is the most transparent and clean sounding of the tubes I have. The NOS Svetlana rectifiers and mu tubes I have are a bit fuller and warmer sounding. I will try these together with the 2A3/SE soon...
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Regards, Morten
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Old 30th September 2012, 10:32 AM   #403
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Join Date: Oct 2006
Location: Karalee, Queensland
Morten, if you can borrow a GEC or Cossor or Osram or Brimar-Osram or Mullard-Osram U52 (5U4) rectifier, they sound extremely good in the Tram2. I borrowed one for my audio meeting and it made an audio difference for the better. You can have a look at the U52 tubes at www.natubes.com.

Are the NOS RCA 2A3 tubes single plate or are they double plate.

Regards

Peter

Last edited by ptashton; 30th September 2012 at 10:34 AM.
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Old 30th September 2012, 10:39 AM   #404
Desmo is offline Desmo  Denmark
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It's hard (impossible) to borrow exotic tubes here in little old Denmark, but once I start looking for tubes again I will check out the ones you mention. Thanks..! I'm happy with the rectifiers and mu tubes I have since the different ones I have can be used to -slightly- tweak the sound.

My RCA's are double plates. I will never ever pay the insane prices for the single plate ones (when the price for a pair of questionably quality single plate NOS tubes can buy me two pairs of better sounding and better quality Full Music 2A3/C or /SE), but that's just me I know that they are from China, new production and that it's ''all the bad stuff'', but I don't care... Hearing is believing

Here are descriptions of my tubes: Tram 2 45 tubes
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Last edited by Desmo; 30th September 2012 at 10:44 AM.
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Old 1st October 2012, 12:46 AM   #405
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Morten, it might take a while, but I have a friend in Sydney who has thousands of tubes. I will ask him to send up a pair of tested single plate RCA 2A3 to try. I tried some secondhand 245 RCA tubes but they sounded dull compaired to the Full Music ST 45 tubes.
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Old 1st October 2012, 08:10 AM   #406
Desmo is offline Desmo  Denmark
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I'm looking forward to read your evaluation of them (and man it must be nice to know someone with so many tubes to borrow from) From what I have heard/read then the single plates are better, but not by a lot, and the prices are high... Based on my experience the risk is also high with these old tubes, especially in a design like the Tram II that is so tube-sensitive.
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Old 1st October 2012, 09:57 AM   #407
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Morten, see http://www.diyaudio.com/forums/attac...system-now.jpg for the person I am borrowing the tubes from.
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Old 8th October 2012, 09:08 PM   #408
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Default B+ Voltage

Hello everyone
I just have finished my Tram2 and following the test protocol. I have now two issues:
- The B+ Voltage should be 250 V. I am getting 440V without tubes.
- The voltage between triode grid and ground should be -65V. I am getting -110V
I would appreciate any recommendations. After assembying the unit Im so eager to hear it, that i cannot wait anymore.
I am located in Germany at 230V

Regards

Marybety
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Old 9th October 2012, 09:25 AM   #409
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Join Date: Oct 2006
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Marybety to answer your question please read the e-mails to Simon at DIYHIFI Supply and his reply:

I
On 5/21/2012 5:57 PM, tpashton@bigpond.com wrote:
> Simon, can you also the technician the following.
>
> When I am doing the post build-up testing and adjustment on the Tram2,
> I was able to obtain 2.7 V for the filament supply at step 6 page 24
> of the Tram 2 V1.34 Manual.

> Next I when measured the voltage required at step 8 page 24, I was
> unable to obtain -65V (+/-10V). On the Fluke 85 Digital Multimeter,
> I obtained -110.7 V on the right Channel and -111.8 V on the left
> Channel. During this test and referring to page 18 Step 3 picture
> detailing voltage measurements.
>
> I then inserted the NOS 5U4 rectifier tube and 6AS7 NOS tube into the
> Tram2 sockets per numbering on the top cover of the pre-amp. I
> measured 216 Vac-0-216 Vac on the input to the Universal Power Supply
> Version 2. This would be because I have 240.5 Vac from the wall
> socket. On the output of the universal power supply, I was reading
> 461 Vdc on the B+ to ABS ground per requirement of page 25 paragraph
> 12. It indicates there should only be 250 V and not 461 Vdc. I also
> read -118 Vdc on the Bias . I should have 220 Vdc on the B= and -74
> Vdc on the Bias. I dare not continue with paragraph 16 to measure 120 V +/-5V.
>
> > Please help.
>
> Peter

Answer from Simon:

uploaded a revised manual 1.35 because for the new filament supply
need to insert tubes for testing otherwise the voltage will goes very high

Tram 2 Manual | Diy HiFi Supply

Then:

Simon, is the FCPSU at the Bias point measuring –74 volts. That is the issue with the FCPSU. I measured –118 volts.


Thanks

Peter

Answer: sorry i misunderstood. they measured -110v of FCPSU. It's correct.


regards,
Simon

So you insert the tubes and the Bias is -110 volts

Last edited by ptashton; 9th October 2012 at 09:28 AM.
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Old 9th October 2012, 10:35 AM   #410
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Thanks a lot four your answer Ptashton.

I tried yesterday with the 274B (5U4) and 6N5P (6as7) tubes.
The B+ voltage without tubes was 440V. With tubes it increased slowly until 400V when I turned the preamp off in order to avoid any damage as the max plate voltage of 6N5P is 250V.
Should I wait longer until it stabilizes?
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