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Old 1st January 2013, 09:19 AM   #511
kazap is offline kazap  England
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... moving right along ....

Phase Issue

The Tram2 inverts phase according to my hero above.

Does this matter to anyone?

I guess most users just switch speaker cables at the speaker posts but Im using these active speakers via an RCA line in (no XLR-balanced socket input):

Click the image to open in full size.


So what do I do?

I guess swapping the RCA wiring in the interconnect between the preamp and active speaker, so the inner 'hot' (signal) is connected to the outer 'cold' (ground) would switch phase but be bad news with the loss of the common ground. I say "guess" as I really have no clue. Please set me straight. Thanks.

Last edited by kazap; 1st January 2013 at 09:24 AM.
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Old 1st January 2013, 10:56 AM   #512
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Hugh, in the Tram2 manual, there is no mention of phase invert of the interconnects. Do you have it in writing from your hero. I have not read it in any on line threads.

Peter
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Old 1st January 2013, 11:07 AM   #513
Desmo is offline Desmo  Denmark
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Yes, the Tram II inverts polarity..! (it's mentioned in the beginning of the thread somewhere). So it's recommended to swap the phase on the speaker cables for correct phase.

Hugh; no you can't just do that (with the rca cables). If I were you I would give the guys who make your speakers a call and say you need to invert polarity. I'm sure they will help you to do so.. The woofers are easy, but they must recommend the best place to swap polarity on the electrostatic element. Or if you don't want to do that, then just play with reverse polarity and try to forget about it...
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Old 1st January 2013, 11:41 AM   #514
kazap is offline kazap  England
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Quote:
Originally Posted by ptashton View Post
Hugh, in the Tram2 manual, there is no mention of phase invert of the interconnects. Do you have it in writing ...
ThorstenL Click the image to open in full size.
"Does the Tram 2 invert phase? Can't find any mention in the manual"

Yes, it does. Any true single stage tube circuit inverts polarity... Ciao T


So the Tram2 puts out an inverted signal from its RCA outputs so you might want to reverse your speakers cables there Peter.

Quote:
Originally Posted by Desmo View Post
..give the guys who make your speakers a call and say you need to invert polarity .
Brilliant idea. Thanks
At the moment it wont be an issue as I use an Audiophilleo1 USB-SPDIF device which inverts phase digitally with a flick of a joystick (I kid you not). Later when I ditch it for one of the USB-I2S boards from this site it will be harder.

Last edited by kazap; 1st January 2013 at 11:47 AM.
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Old 1st January 2013, 10:38 PM   #515
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Hugh. I have a Tram2 which inverts phase which goes into the STC 4212E amps single ended which inverts phase. I was told that my amps phase inverts so what I did was to listen to the normal and then inverted phase to the speaker connection. The phase inverted connection sounded better to myself and Keith Eichmann. So if you invert then invert again you should come up with normal phasing which should sound best. In my case it did not. I'm sticking with the phase invert connections to the speakers. It is what sounds best to your ears and not get hung up on technicalities.

Peter
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Old 2nd January 2013, 06:23 AM   #516
kazap is offline kazap  England
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Quote:
Originally Posted by ptashton View Post
... I'm sticking with the phase invert connections to the speakers. It is what sounds best to your ears and not get hung up on technicalities. Peter
Thanks Peter. I agree with you that listening is always the most important thing. Thanks for so generously coming around today so I could hear your lovely Tram2 again. It sounded so good I clean forgot to experiment with switching the phases around. I must try and remember to get more hung up on technicalities next time.
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Old 2nd January 2013, 09:09 AM   #517
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Hugh, unfortunate for you, you can not at the moment phase invert, as you only have RCA connectors to your powered speakers. You need to have those earths on electrical equipment.

Listening to the Tram2, this pre-amp has something special to add to the music. This is in it's standard form only with NOS tubes.

It would be interesting to contact the manufacturer of the speakers to phase invert the speaker drivers. It would be a matter of unscrewing the back amp panel and making the necessary terminal changes if necessary.

You should check if the Melody pre-amp is phase inverting. The plot thickens!!! The music sounded really good anyway.

Last edited by ptashton; 2nd January 2013 at 09:14 AM.
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Old 2nd January 2013, 09:58 AM   #518
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Hmmmm i am 100 procent shure that i have ask ,about the inverting to Diy Hifisupply..in the mail they write that the Tram don't invert the phase
now i have just tried to swap the speaker cable---not bad for the sound ,,voices more upfront---good that this problem come to my ear
thanks for that
Bjarne
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Old 2nd January 2013, 01:34 PM   #519
kazap is offline kazap  England
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My next query is around the best design for tube "chimneys" for the Tram2.

I understand that originally these chimneys were designed to facilitate an updraught around the tubes to enhance cooling:

Click the image to open in full size.

The Tram2 DHT's benefit from EMF shielding to reduce hum and might also benefit form microphonic reductions via shielding from airborne resonance.

So in the Tram2 tube chimneys might offer three function
a. enhanced convection cooling
b. electromagnetic field shielding
c. vibration shielding to reduce physical resonate and microphonic induced noise

Would you recommend I make tube chimneys from:

1. Steel pipe with thick walls


Click the image to open in full size.

2. Copper Pipe

Click the image to open in full size.

3. Copper sheet 1MM think that can be hand crafted to fit:

Click the image to open in full size.
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Old 2nd January 2013, 03:05 PM   #520
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I use the steel pipe for the 2a3 tubes---works ok
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