Valve Itch phono - Page 4 - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 2nd December 2010, 12:28 AM   #31
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Default Another Itch

Went to Mikvous's place today to examine another Itch he made. With my Rev1 changes included.
Attached Images
File Type: jpg DSCF2495.JPG (467.2 KB, 1083 views)
File Type: gif ItchRev1.gif (7.4 KB, 1352 views)
  Reply With Quote
Old 2nd December 2010, 01:12 AM   #32
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Default Some Details

It has a Dynavector DV6Z step up taken out of its original box and put inside as the silver cylinder in the pictures. Also a Simpler Simplistic HV and two filament regs in the same box. Another box houses the transformers and the rectification/filtering. Feeds DC lines to the regs through a cable to that multi-pin connector which can be seen in the back panel and underside pics. The PSU is like in post #3. Changes are my HV shunt reg instead of the Maida, and equal value resistors in the heater lift network since the upper cathodes sit higher in this revision. Either the tube model's Rp/Miller played a role or the SUT shapes response, but we took out the extra 1nF Silver Mica across the *15nF nominal MKP Arcotronics Riaa caps after we measured its filtering curve with pink noise. Listening before & after confirmed. It hits 0.08% with 2mV input without the SUT, second harmonic only. 0.1% with 0.5mV and SUT. We just swapped the output Melz 6H8s between channels and a couple of 6N2PEVs for the lower tier input valve and got 0.33dB channel gain agreement. Noise floor in both cases starts at -80dB at 20Hz and falls to -120dB at 20kHz following a Riaa like attenuation shape. That is for 0dB=1VRMS calibrated. Sounds really quiet for a valve phono. Plus you can hammer it and get zero microphonics. Actually Michael had it fallen from 1.5m height to concrete floor while playing and did not make a sound other than music. Subjectively he is head over hills with it. I find it very nice too. Its better than the first easily. Will listen to more records with it in an audition only mates gathering soon.

*15nF nominal 5-10% caps can be 15n++. 15.3nF measured value with a tight & calibrated desktop meter should be ballpark.
Attached Images
File Type: jpg DSCF2488.JPG (308.4 KB, 1080 views)
File Type: jpg DSCF2489.JPG (344.8 KB, 808 views)
File Type: jpg DSCF2490.JPG (564.0 KB, 841 views)
  Reply With Quote
Old 2nd December 2010, 01:16 AM   #33
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
Still more temptations!!!!!
__________________
Living Life Doing the Waltz in 4/4 meter.
  Reply With Quote
Old 2nd December 2010, 01:29 AM   #34
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Have made many valve phonos, this one I recommend without hesitation. You can see a 12B4A pre in the background among other things...
  Reply With Quote
Old 2nd December 2010, 01:36 AM   #35
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
Yep, I see it now that you pointed it out. My 12b4 remake is first on my agenda, then the V1.2R, and then finally may have time for this one. Will need another head amp when the nanook arm comes in.
__________________
Living Life Doing the Waltz in 4/4 meter.
  Reply With Quote
Old 2nd December 2010, 09:53 AM   #36
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by SGregory View Post
Still more temptations!!!!!
+1

Just finished V1.2R, so please Nick stop to do a lot of very good projects I don't have time to follows you (money & time)...
  Reply With Quote
Old 2nd December 2010, 05:51 PM   #37
diyAudio Member
 
Join Date: Nov 2004
Location: Bruchsal/Germany
Hallo Salas ,

whats the difference between Dynavector DV 6 Z and mine DV6 X .
Can you please explain the difference ?
Thanks in advance !

Greetings
Jürgen
  Reply With Quote
Old 2nd December 2010, 05:59 PM   #38
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
X is 1:20, Z is 1:10. 30kHz bandwidth both. DV6A is 1:13 70kHz bandwidth and most expensive.
  Reply With Quote
Old 2nd December 2010, 07:51 PM   #39
diyAudio Member
 
Join Date: Nov 2004
Location: Bruchsal/Germany
Hi Salas ,

Mille Grazie !

Jürgen
  Reply With Quote
Old 2nd December 2010, 07:55 PM   #40
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Nothing much.

P.S. Here is a pic I found on the web so for people here to see what was that cylinder in its former life before I donated it to the Itch.
Attached Images
File Type: jpg DV6Z.jpg (78.1 KB, 534 views)
  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
Got the build itch again. 80w kt88 itsmejto Tubes / Valves 44 26th September 2008 11:49 PM
valve phono stage wanted for mc brobarrie Swap Meet 1 13th August 2007 08:17 PM
Basic DIY Valve Phono Stage matthew2456 Tubes / Valves 5 29th March 2007 04:11 AM
Phono pre, valve or jfet lndm Analogue Source 7 4th April 2006 02:11 PM
phono preamp design for c3m postie valve fergs1 Tubes / Valves 1 29th May 2005 02:12 PM


New To Site? Need Help?

All times are GMT. The time now is 04:00 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