DHT OTL Linestage - Tram 2

[Desmo]

@Hugh... Yes, installing the Rod Coleman regulators on the chassis sides is possible and much easier than the installation I made... Geir did it, look a few pages back for his installation.

The downside with this is longer wiring at places where one want the wires short. Also, if you see my installation the heatsinks work as grounded shields where all the noisy stuff -wires to and from the rectifiers for instance- is all inside the ''box'' formed by the heatsinks.

But again: Using the sides makes for a very easy installation...

[clivetjm]

The v3 Tram heater supplies are the same circuit as v1 and v2 with some component quality and value changes. I haven't yet tried Rod's heaters so I can't yet make the comparison, I just need to find the time.

[Desmo]

Originally Posted by clivetjm

The v3 Tram heater supplies are the same circuit as v1 and v2 with some component quaility and value changes. I haven't yet tried Rod's heaters so I can't yet make the comparison, I just to find the time.

Hi Clive.

Yes, that was what I thought from the pics of the V.3... Then you (with the V.3's can look forward to the same improvement as we did

BTW. On the Rod Coleman regulators it gives another step of improvements in sound to upgrade the current sensing resistor and one of the caps (see my installation where it's explained). One might as well install these parts from the beginning...

[clivetjm]

Originally Posted by Desmo

Hi Clive.

Yes, that was what I thought from the pics of the V.3... Then you (with the V.3's can look forward to the same improvement as we did

That's what I hope for (and expect).

[ptashton]

Hugh, Morten has done the research and development into the Rod Coleman regulator installation. In your case, it will be much simpler to install these regulators per Morten's design during the assembly of the Tram2 rather than make the modification when you have an existing Tram2. In my case there will be drill swarf to remove from inside the chassis so not to get court against the electrical components. Morten has done it and this installation has worked for him. If you look at the threaded before the Rod Coleman regulator installation, Morten tried the supplied heater regulators with large heatsinks. His regulator installation look extremely neat with short connections between components. No long wires to pick up noise. Noise is what you do not want.
Hugh, you have some good ideas, but you should go with Morten's regulator installation during the Tram2 assembly.

[ptashton]

Hugh, when ordering the Tram2 from DIYHIFI Supply, ask Simon (contact at DIYHIFI) for a price without their heater modules. When I was at their old shop, all they did was assemble the kit from parts on the spares shelf. If you do not ask, you will have extra heater regulator that you will not use. DIYHIFI should utilize the Rod Colemand regulators in their kits. A must better solution.

Peter

[kazap]

Originally Posted by ptashton

...ask Simon (contact at DIYHIFI) for a price without their heater modules...go with Morten's regulator installation... Peter

Originally Posted by Desmo

.... I will recommend getting ten extra caps t to get six of them in each channel....if you see my installation the heatsinks work as grounded shields where all the noisy stuff -wires to and from the rectifiers for instance- is all inside the ''box'' formed by the heatsinks.

thanks guys! Your all very kind and generous with your help.

I want a Tram2-MortenV4b- MusicFirst/2A3/SE

[Desmo]

Originally Posted by ptashton

Hugh, when ordering the Tram2 from DIYHIFI Supply, ask Simon (contact at DIYHIFI) for a price without their heater modules. Peter

That's a good idea, maybe they will swap the heaters for the 10 extra tinfoil caps needed..! You should ask for that Hugh and thanks for the kind words

[Desmo]

Originally Posted by ptashton

No long wires to pick up noise. Noise is what you do not want.

Not picking up noise is one concern, and wires not emitting noise is another. There are big currents running in the DHT regs, and on the ''ac side'' of the regs before and after the rectifiers there are large peak currents meaning that the wires can act as antennaes sending out noise. No matter how the installation is made, it's good to keep these wires as short as possible, and to have ground/shield between these wires and the preamp circuit.

At the other end of the regs, the wires going to the filaments on the triodes sould be considered as in the signal path, so these must also be as short as possible for that reason.

[Desmo]

I don't know why my picture of the RCA tubes disappeared, the user interface at Photobucket is totally changed, so maybe I upload the wrong way. I try once more...

These are the two pairs of RCA 2A3 tubes I have...