|Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum|
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
||Thread Tools||Search this Thread|
|13th January 2013, 12:58 PM||#1|
Join Date: Jan 2008
Dynaco mk3 clone hum issue
I just finished one of the mk3 clone and let me say the sound is exactly like I wanted. The VTA-octal is a must have.
Now I have unresolved grounding issues... (measured 22mv AC at output and 20-22hertz dominant frequency)
Some information on my build:
1. I didn't put the 0.002uf cap with the center tap of the heaters.
2. I grounded the output tubes to the capacitor bank
3. the case is wood and there is no earth attached from the power outlet to the capacitor bank ground.
4. there is a separate transformer for the bias on the VTA octal, one side of the secondary is connected to the bias and the other to the capacitor bank ground.
What I will do next:
The next step was to disconnect the ground from the speaker binding post and attach it directly to the capacitor bank (-) instead of the VTA board.
Any positive input is appreciated from people who knows tricks and amplifiers. Thanks!
(also posted in the dynaco forum)
|Thread Tools||Search this Thread|
|Thread||Thread Starter||Forum||Replies||Last Post|
|Hum issue||e_fortier||Class D||6||3rd March 2009 02:42 AM|
|another Hum issue LM3875||sts9fan||Chip Amps||43||10th September 2007 04:06 PM|
|dynaco st35 clone problem||pascde||Tubes / Valves||3||28th December 2006 03:54 PM|
|Dynaco ST70 clone||Tekko||Tubes / Valves||8||9th April 2005 02:02 PM|
|VERY loud hum issue||5th element||Solid State||23||30th May 2004 05:37 AM|
|New To Site?||Need Help?|