DHT OTL Linestage - Tram 2

[ptashton]

Morten, have a look at this web site. Only US 540.00 for a pair. Full Music 2A3 / SE tube The company is in Hong Kong. Not a bad web site.

[Desmo]

Originally Posted by ptashton

Morten, have a look at this web site. Only US 540.00 for a pair. Full Music 2A3 / SE tube The company is in Hong Kong. Not a bad web site.

Thanks for the heads up! I did see those also, and the price is the same as at Parts Connexion (as long as they have the summer sale). I choose to order from Parts Connexion because I know them, and with expensive tubes like these I prefer to buy from a known source.

[ptashton]

I see DIYHIFI Supplies has come out with version 3 of the Filament Supply. They call it the 'DIYHFS Ultra Low Noise Filament Supply (Rev 3) 2-12V or 12-24v DC jumper selectable (Pair)' Note the 'Ultra Low Noise'. Any opinions from this forum on this new version.

Morten, I will have to look out for the Summer sale at Parts Connexion. Thanks

[GeirT]

Originally Posted by ptashton

I see DIYHIFI Supplies has come out with version 3 of the Filament Supply. They call it the 'DIYHFS Ultra Low Noise Filament Supply

Sure interesting, my Tram kit is in the pipeline so I'm curious to see if they have included the new heater or not. I've also received Rod Colemans heater kit already so I'll try both some day, and report.

[ptashton]

GeirT, where did you purchase your Rod Coleman Heater regulator kit. Do you have any info from Rod that you could share with this forum. Thanks

[Desmo]

Originally Posted by Desmo

Hi Geir, sorry I forgot the link..! You buy them directly from Rod Coleman, just drop him a pb here in diyaudio. There is a long thread about these regulators: New DHT heater


After doing a bit more listening I can honestly say, that this upgrade with the regulators is the one that sonically makes the biggest improvement. More than different tubes, coupling caps etc. And as a big bonus, the noise is also gone with these.

I quote myself on my reply to Geir on that question... Have a look at the DHT heater thread that goes all the way to 2004 and contact Rod Coleman via PM here in DiyAudio to get the regulators... They are submitted with all parts for the regulators, instruction manual, and descriptions on the parts t
you need for the raw-dc supply.

[ptashton]

Morten, thanks for your response. I will have a look at the New DHT Heater thread.

[Desmo]

Originally Posted by ptashton

Morten, thanks for your response. I will have a look at the New DHT Heater thread.

Your welcome... If you take your time to read / understand the thread, there is a lot of knowledge there. About voltage regulators, and current regulators. About regulators based on IC's with hard feedback that can effect the heaters/sound and discrete regulators that does not interfere in the same way etc etc...

[ptashton]

Morten, I just purchased Rod Coleman's Regulators. He sent me two PDF instruction manuals. What power supply circuit components did you use in the Tram2. It would help me greatly. Thanks Peter

[Desmo]

I used this one (from his older manual), but without the fuses on the DC side. If you have any doubts about what's best to do/use, then just ask him in the DHT heater thread, he is very helpful...



The most critical is the rectifier diodes and especially the first caps after the rectifiers. I used MBR1045 diodes and RIFA PEH200, 10.000uF-40V as C1. The RIFA's are big and a bit expensive, but they can handle 12A ripple, so they are exellent for this purpose. They are the two big white caps in my installation if you look at the pics. I can't remember the manufacturer of the C2 caps, but they are also 10.000uF - 40V types with a ripple capacity for around 4A or so. Check your local supplier and choose caps according to ripple handling - it's all well described in Rod Colemans instruction manual. For the rest of the components I used what I had...

I will recommend the upgrade of R1 and C3 on the regulator modules (there is lot's on this in the DHT heater thread). I used 12W Mills 0.47 ohm resistors and Amtrans 220nF caps. Both are relatively cheap and the sonic improvement in dynamics and clarity is worth it. They can fit like this...