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Old 31st December 2012, 06:42 AM   #491
bronal is offline bronal  Australia
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Default Time for a Tram 2 MkII?

The Tram 2 has been around for a couple of years now and the issues with the original design have been identified and solutions proposed by the DIY community. My personal view is that the Tram 2 is a world-class concept but was released to market too soon and that anyone interested in a Tram (and, like me is not DIYer) who reads this thread could be put off buying by what appear to be a multitude of shortcomings that have to be addressed.

So, isn't it time for a MKII version incorporating all the knowledge that has accumulated over the past couple of years? I myself would appreciate a bigger case allowing a choice of different capacitors and better ventilation to allow heat to escape.

Any other views?
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Old 31st December 2012, 07:11 AM   #492
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Quote:
Originally Posted by kazap View Post
a. removing the epoxy paint on the chassis inner side wall to achieve a smooth raw aluminium exposed surface to maximise heat conduction transfer

Either mounting the transistors using heat conducting tape

OR better still: screwing the transistors into the side wall if you have a deft touch so as not drill though the chassis (perhaps wind tape around the drill to build up a 2mm wide collar allowing a safe drill depth 1mm shorter then the case thickness).

Use a copper shim for best heat transfer between the transistor and chassis and plenty of Thermal conducting CPU paste between all surfaces.

b. sticking heat insulation tape to the inner chassis wall adjacent to the transistor mounting; with the aim of minimising heat transmission back inside the case

c. optionally sticking heat sink fins on the outside of the case (if you don't like the look or they don't drop temperature appreciably just pull them off)

4. Put aluminium shielding on the inner side of the regulators to minimise stray electrical fields and further minimise radiant heat transfer - the fins of that linked heatsink will need to be flattened back with a hammer leaving just the top fins as a mounting base to the underside of the top plate. The inner vertical surface should have the thermal-electrical insulation tape glued to it.

Cheers
Hugh
Hugh,

I like the shim (heat spreader plate) best.

It can be Alu (though Copper is best if at hand). 5mm thick or more is best. Something like 100mm x 60mm will make a difference - and increase either dimension if possible.

Filaments start up from cold at lower resistance - so there is a lower voltage across the filaments at switch-ON. The difference between cold & hot voltage is soaked up but the Regulator transistor Q5 during the couple of seconds of warm up.

A spreader plate helps with this thermal surge, and means that the removal of the epoxy paint is less critical.


Either way, the transistor cases should be at less than 70 deg C (Absolute max) and preferably below 55 deg C.
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Old 31st December 2012, 08:31 AM   #493
Desmo is offline Desmo  Denmark
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Quote:
Originally Posted by bronal View Post
The Tram 2 has been around for a couple of years now and the issues with the original design have been identified and solutions proposed by the DIY community. My personal view is that the Tram 2 is a world-class concept but was released to market too soon and that anyone interested in a Tram (and, like me is not DIYer) who reads this thread could be put off buying by what appear to be a multitude of shortcomings that have to be addressed.

So, isn't it time for a MKII version incorporating all the knowledge that has accumulated over the past couple of years? I myself would appreciate a bigger case allowing a choice of different capacitors and better ventilation to allow heat to escape.

Any other views?
I agree with you that the Tram II might have appeared a bit ''unfinished'' when it was first released, but to be fair and respectful to the designers, then the only issues has been the insufficient cooling on the DHT regulators. Since the Tram II is build up by diy hifi supply modules and parts, then I don't think it's likely for them to source an ''outside product'' like the Rod Coleman dht regulator. But that's just me speculating...

Everything else is a matter of design choices, and that the preamp must match a certain price point in the market - this means that the most exotic components are not used.

Personally I love the way this is a ''very finished DIY platform'' we can then work on, and I believe that is also the way it's intended. I remember reading (think it was Thorsten who mentioned it), that even if one buys a Tram II build by diy hifi supply, then it should still be considered DIY and needing some work.

The small chassis makes work and upgrades challenging, but I like the size and the design. It's even cooler to have two of these chassis side by side

Click the image to open in full size.
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Old 31st December 2012, 09:28 AM   #494
bronal is offline bronal  Australia
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Is that a Plinius I see? Which model? I'm using my Tram with an SA-50 that Decky has just refurbished for me. The sound is humungous, even at -12dB. A marriage made in heaven!
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Old 31st December 2012, 09:35 AM   #495
Desmo is offline Desmo  Denmark
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Originally Posted by bronal View Post
Is that a Plinius I see? Which model?
Yes It's a Plinius SA-REF...
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Old 31st December 2012, 11:57 AM   #496
kazap is offline kazap  Australia
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Having listened to a Tram2 thanks to Peter I simply cant imagine any other pre could sound better for me.

But 26 tubed type preamp owners have hinted to me they cant imagine any other DHT design could improve on a 26 based pre with quality output transformers.

I dont want to start a big discussion but I do wonder if anybody has actually heard both?
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Old 31st December 2012, 12:17 PM   #497
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I can't comment on a 26 but bear in mind a significant feature of the Tram is that it does NOT use output transfomers.
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Old 31st December 2012, 12:59 PM   #498
Desmo is offline Desmo  Denmark
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Originally Posted by kazap View Post
But 26 tubed type preamp owners have hinted to me they cant imagine any other DHT design could improve on a 26 based pre with quality output transformers.
And others with yet another style of preamp can't imagine that anything can be better than what they have... And so it goes, on and on and on... Hearing is believing..!
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Old 31st December 2012, 11:06 PM   #499
bronal is offline bronal  Australia
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Quote:
Originally Posted by Desmo View Post
I agree with you that the Tram II might have appeared a bit ''unfinished'' when it was first released, but to be fair and respectful to the designers, then the only issues has been the insufficient cooling on the DHT regulators. Since the Tram II is build up by diy hifi supply modules and parts, then I don't think it's likely for them to source an ''outside product'' like the Rod Coleman dht regulator. But that's just me speculating...

Everything else is a matter of design choices, and that the preamp must match a certain price point in the market - this means that the most exotic components are not used.

Personally I love the way this is a ''very finished DIY platform'' we can then work on, and I believe that is also the way it's intended. I remember reading (think it was Thorsten who mentioned it), that even if one buys a Tram II build by diy hifi supply, then it should still be considered DIY and needing some work.

The small chassis makes work and upgrades challenging, but I like the size and the design. It's even cooler to have two of these chassis side by side

Click the image to open in full size.
I'll go along with the chassis bit but it doesn't make sense to me to keep offering a product with known issues when they can be fixed up so easily.
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Old 1st January 2013, 12:51 AM   #500
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Has anyone contacted Simon at DIYHIFI Supply with the modifications on this thread to see if they would implement the improvements in their product. This could include a module circuit board of Rod Coleman's regulator. It would be very good to see his regulators and power supply modulized to fit into the Tram2.

Peter
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