2. amps-preamps
  3. 166977-155971

Tube Bias question

Good morning everyone,
Recently I bought some new tubes for my Mac 240. 6l6 GC Tung Sol reissues. 
I had ordered the matched quad set. Issue was I only received two, made the dealer aware of the mistake and they did a great job of fixing the minor mistake. I received the remaining two yesterday. The concern I have is they are not a matched quad set. The first two had a matched bias of 44 or so, the next pair were matched at 53. Please excuse my ignorance as to what the translation is.
My question is this. I have read that the old Mac is not an amp that is sensitive to bias, or that it matters much. 
I was going to install one matched pair for each channel. Will this have a noticeable or negative effect on sound?
My system.
MoFi Ultra Deck 
Cambridge phono pre-amp
NAD pre amp and CD
MAC 240 amp (refurbished by Audio Classics Ryan. Awesome experience BTW)
Heresy iv
SVS PB 2000
Appreciate any feedback.

Thank you,
Doug

doyle3433

Showing 1 response by oldhvymec

oldhvymec
5,101 posts
 
Get a set of 4 within 5% and you have a GOOD matched set. 10% is not uncommon. Golden Lyon is 10%.  Make sure you make your position clear. Not their match YOUR match.. 5%.. NOT 10%

4 pieces within 5% same date stamp. There are just too many out there NOT to get what you paid for. 25-375.00 usd..

RCA BL expensive. 2-400.00 quad

Everything between

New Russian surplus, 29-69.00 quad. There are some good surplus valves too.  A set of 6 gives you two spares. 59-69.00. 10 years of service.. 10 hours a week is 10 years @ 5000 hours..

IF you add a soft start they will last even longer.  

Regards
More to discover