DHT OTL Linestage - Tram 2 - Page 69 - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > DIY HiFi Supply

DIY HiFi Supply Parts and Kits from Diy HiFi Supply

Reply
 
Thread Tools Search this Thread
Old 8th April 2013, 06:10 PM   #681
Desmo is offline Desmo  Denmark
diyAudio Member
 
Join Date: Jan 2007
Location: Aarhus
I agree, I see the circuit the same way, the 6AS7 is the top of the super-mu (as it's also described by the designers in the beginning of the thread)... Sometimes I just can't find the proper words in English to describe what I mean. Describing technical stuff in a second language is not easy (for me), I knew it was not really correct when I wrote that the 6AS7 is in the final stage of the PS, and when I wrote it I expected that someone would ''correct me'' My point was, that it's not directly in the signal path doing signal amplification as in those headamps, I just could not find better words. Thanks for clarifying with a more proper description, links, references and all...
__________________
Regards, Morten

Last edited by Desmo; 8th April 2013 at 06:30 PM.
  Reply With Quote
Old 8th April 2013, 06:38 PM   #682
sjs is offline sjs  United Kingdom
diyAudio Member
 
Join Date: Oct 2011
Location: Manchester
Morten, thanks for your work on the Tram2, I think you have inspired many owners to take the next steps.... I am currently waiting for a few parts before putting Rod Coleman heater supplies in place in order to remove the caps across the filaments....
  Reply With Quote
Old 8th April 2013, 09:11 PM   #683
Desmo is offline Desmo  Denmark
diyAudio Member
 
Join Date: Jan 2007
Location: Aarhus
Thanks.... I believe that DIY is about sharing, and not holding the best bit's and pieces back as secrets as some DIY'ers do... Let us know what you think after installing the Rod Coleman regulators
__________________
Regards, Morten
  Reply With Quote
Old 8th April 2013, 09:55 PM   #684
kazap is offline kazap  Australia
diyAudio Member
 
kazap's Avatar
 
Join Date: Apr 2011
Location: Brisbane
Quote:
Originally Posted by sjs View Post
...... In other uses I prefer 6080 over 6AS7, but unfortunately they are tricky to use in the Tram2 due to the size of the base on most 6080s.
That's interesting. Thanks Simon. May I ask you a couple of questions?

I have plenty of 6080's but found , like you that they just dont fit through the Tram2 top plate. Have you get any thoughts about the easiest way to enlarge the Tram2 6AS7 top plate opening to let the 6080 in?

Also since you understand the circuit and I dont do you think any 6AS7 type variants that have higher mu factors then the 6AS7/6080 mu=2 would be OK to try or are they going to push the circuit out of designed spec's?
  Reply With Quote
Old 8th April 2013, 10:14 PM   #685
gjm is offline gjm  United Kingdom
diyAudio Member
 
Join Date: Sep 2009
Quote:
Originally Posted by Desmo View Post
Thanks.... I believe that DIY is about sharing, and not holding the best bit's and pieces back as secrets as some DIY'ers do... Let us know what you think after installing the Rod Coleman regulators
I'm happy to share all and any of my experiences, in the tiniest detail.

It'll make a good "How not to..." series! Fortunately I'm now beyond being embarrassed.
  Reply With Quote
Old 8th April 2013, 10:35 PM   #686
sjs is offline sjs  United Kingdom
diyAudio Member
 
Join Date: Oct 2011
Location: Manchester
Quote:
Originally Posted by kazap View Post
That's interesting. Thanks Simon. May I ask you a couple of questions?

I have plenty of 6080's but found , like you that they just dont fit through the Tram2 top plate. Have you get any thoughts about the easiest way to enlarge the Tram2 6AS7 top plate opening to let the 6080 in?

Also since you understand the circuit and I dont do you think any 6AS7 type variants that have higher mu factors then the 6AS7/6080 mu=2 would be OK to try or are they going to push the circuit out of designed spec's?
I think they were mentioned earlier in the thread, but an octal socket saver is probably the best place to start for experimenting, something like this:
VACUUM TUBE 8 PIN OCTAL SOCKET SAVER for 6L6 6V6 6SN7 EL34 ST8-1000 on eBay!

As for using the near equivalent valves with a higher mu, I am not certain as I haven't really thought about it. Could be worth running a few sims to check it out. The brief look through the links I posted earlier seem to make me think it shouldn't be a huge problem, but it is whether any of the circuit needs a tweak to work with the change in tubes, and I cant answer that at the moment as I have not actually played around with the circuit.
  Reply With Quote
Old 9th April 2013, 10:08 PM   #687
kazap is offline kazap  Australia
diyAudio Member
 
kazap's Avatar
 
Join Date: Apr 2011
Location: Brisbane
Thanks Simon - that's very useful.
  Reply With Quote
Old 26th April 2013, 11:34 AM   #688
rab28 is offline rab28  Australia
diyAudio Member
 
Join Date: Jan 2010
Location: Melbourne
Quote:
Originally Posted by Desmo View Post
Richard, I think your own diagnosis is correct: You have a dead DHT regulator board...
Hi all, so my brand new but faulty Tram2 went to the doctor and is currently undergoing surgery. Turns out that one of the CCS modules was dead and there were multiple earthing faults.

The earthing issues have been fixed, and the Coleman regulators have been installed.

While the amp is still in surgery and waiting for a replacement CCS kit (thanks Simon!), i decided to order some Duelund Alexanders for input caps, Mundorf Supremes for output caps, Audio Note tantalum resistors, and one of those Philips rectifer tubes.

In the meantime, a friend who had just installed Coleman regulators brought his Tram2 around for a few hours of listening -- this Tram2 is stuffed with premium parts, including wire. My goodness it sounded good! Just beautiful to listen to... and this is with brand new parts, not run-in at all, and also relatively cold.

So now i am even more excited and feeling very impatient to get mine running!!

- richard
  Reply With Quote
Old 26th April 2013, 11:45 AM   #689
Desmo is offline Desmo  Denmark
diyAudio Member
 
Join Date: Jan 2007
Location: Aarhus
Hi Richard,

Great to hear, that you are getting the preamp repaired Please remember to upgrade the cap + resistor on the Rod Coleman modules, it gives a nice improvement for little money and is so much easier to do before the modules are installed, than after...

Nice parts you are getting... The Duelund Alexander's has a slightly warmer and slightly less transparent sound compared to the more expensive models, but they still have the amazing natural sound that is the ''Duelund sound'', or maybe one should say lack of sound. It's one of those products that I'm proud of saying comes from our lille country

Nice with the other parts..! Personally I prefer the Shinkoh tantalium resistors over the AN, but all tantaliums are really nice... Also IMHO the Obbligato tinfoils are better than the Mundorf supremes for output caps, if you are talking about the standard Supremes that is? If you are going for the Supreme silver/gold/oil that is another story, but costly and takes up a lot of space since at least 12uF is needed...

Besides the Philips rectifier, what kind of tubes will you be using..!?
__________________
Regards, Morten

Last edited by Desmo; 26th April 2013 at 11:50 AM.
  Reply With Quote
Old 26th April 2013, 12:27 PM   #690
sjs is offline sjs  United Kingdom
diyAudio Member
 
Join Date: Oct 2011
Location: Manchester
Quote:
Originally Posted by Desmo View Post
but costly and takes up a lot of space since at least 12uF is needed...
You only need 12uF if you retain the voltage divider network on the output, and have a SS power amp with low input impedance, as it appears to have been designed to work with loads down to about 10K.

Personally I have reasonably low sensitivity valve power amps with 100K input impedance, so I have replaced the voltage divider with a more regular 1M0 resistor, and the 12uF Obliggattos with 1uF Hovland output caps.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
C3M linestage costa23 Tubes / Valves 15 23rd August 2009 08:53 AM
C3m linestage bequerel Tubes / Valves 32 14th April 2009 06:03 AM
48V B+ linestage hirafu_boarder Tubes / Valves 24 11th May 2008 05:57 PM
Another linestage...... kianbach Tubes / Valves 11 28th June 2005 05:34 PM
:: linestage [Bryston B60] :: dhengkoel Solid State 6 26th September 2002 03:32 PM


New To Site? Need Help?

All times are GMT. The time now is 12:10 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2