I recently purchased a matched quad of inexpensive Shuguang EL34s from eBay to try in my VTA-70. They show no signs of distress after about 40 hrs. and all have biased the same at about the 1:30 position on the bias pots for a setting of 0.40v.
Shuguang EL34
I have tried bias settings from 0.35v to 0.45v, with the higher setting giving a more detailed sound, but the lower setting seems to have more of that "tube magic." How high/low can I go before I create problems for the VTA-70? At only $34 for the EL34s I'm not really concerned that much about extending the life of the tubes.
I marginally prefer the Shuguangs warmth and openness to the cryoed EH6550s I had been using ($159). I also like the looks of the smaller bottle. The 6550s look a little too chubby for the chassis.
Thanks for looking,
Gregg R.
I hear larger differences swapping driver tubes than in switching power tubes. Is that to be expected?
Shuguang EL34
I have tried bias settings from 0.35v to 0.45v, with the higher setting giving a more detailed sound, but the lower setting seems to have more of that "tube magic." How high/low can I go before I create problems for the VTA-70? At only $34 for the EL34s I'm not really concerned that much about extending the life of the tubes.
I marginally prefer the Shuguangs warmth and openness to the cryoed EH6550s I had been using ($159). I also like the looks of the smaller bottle. The 6550s look a little too chubby for the chassis.
Thanks for looking,
Gregg R.
I hear larger differences swapping driver tubes than in switching power tubes. Is that to be expected?
Last edited by Gregg R. on Fri Jul 18, 2014 1:37 am; edited 1 time in total (Reason for editing : Added Question)