Cayin TA-30 Operating Instructions/Biasing

It's very unfortunate that Paul Grzybek of Tube Audio Design passed away as he modded all the TA-30 units he sold to where they were easily biased from the outside. He mentioned that unless you know what you're doing, it can be quite dangerous. I would stay away from any unit where you have to do biasing from the inside as you have to turn it on, turn it over, and remove the bottom plate.

Having said that, the value you are looking for is .35V. Here is an article from 'Goodsound' that tells you. It's in the 7th paragraph down:
http://www.goodsound.com/equipment/cayin_ta_30.htm

I really enjoyed mine when I had it but it does put out a lot of heat.

All the best,
Nonoise

Best to contact Steve at cayinusa.com. Steve is the distributor of Cayin in the usa, and is always there to help.

Paul's passing came as a surprise to me. I was hooked up with Paul on Linkedin and we had a friendly relationship. He was always good for advice.
I used to have a set of instructions from Paul, but I may have discarded them with the sale of my previous unit.
Thanks for the contact at Cayin USA.
John

"You will need a tiny screwdriver and the supplied digital voltmeter to set the 4 output tube bias adjustments. Switch the amplifier on. Let it warm up for at least a few minutes. Plug the digital voltmeter Black lead into the Black tip jack and the Red lead into one of the Red jacks. (turn meter on, set meter to the marked 2000mV range). MEASURE WITH THE VOLUME ALL THE WAY DOWN - NO MUSIC PLAYING. You should see a reading on the meter. Turn the corresponding 25-turn small adjustment screw for each red tip jack you are measuring till the meter reads 350 (mV). Now move the red probe to the next tip jack and adjust the next corresponding adjustment screw. Repeat all 4 adjustments a few times till all are reading 350 (mV) +/- 10%. Super easy! The bias should be checked immediately when new tubes are installed, then every 6 months there after. Unusual readings (after initial adjustment - very high or very low compared to the other tubes indicate a tube failure. Output tubes generally last around 3000 hours. So every 1-3 years you will need replacements. A computer matched quad is the best choice - but not absolutely necessary in this separate tube bias design."

*** NOTE FOR KT-88 TUBES *** Bias to 400

Bias into class A - using tubes 1 & 3 (pull 2 & 4 out) - set bias to 700(mV) (assuming 800(mV) for KT-88)
This will convert the PP amp to single ended

So sorry to hear about Paul's passing

Dwhall covered it perfectly.
I'm saddened to hear about Paul. I got an original TA-30 amp second-hand and had it sent directly to Paul for the upgrade/mods. Paul handled it as if I bought the unit directly from him. He offered lots of objective advice and wasn't afraid to tell things straight. You could tell this was his passion, not just a business. A true gentleman. He will be missed.
The TA-30 was a great unit made even greater with the BizzyBee mods. No other Cayin approached it's price/performance ratio imho. I still own this unit because, for the money, nothing beats it.