Latino ST120 with VTA SP9 & PH12

I’m officially a full VTA convert.

I had an original ST-70 with some Dynakitparts upgrades and really enjoyed it, then added a VTA SP9 with the PH12 phono board. Loved it. Then ran across opportunity to grab a fully upgraded Bob Latino ST120 and I’m in love.

SP9 with 4x NOS Telefunken 12ax7’s
PH12 with 2x NOS Amperex 6922’s

ST120 with Sovtek 6550we’s (def wanna try the TS KT120’s)
Upgraded caps
Auto bias board
Stepped attenuator
Bias level LCD’s

Are the meters on the front only measuring the front two tubes? Or is there a switch hidden so that the rear pair can be monitored? Not really necessary if the AB is working ok. Enjoy....

pichacker wrote:Are the meters on the front only measuring the front two tubes? Or is there a switch hidden so that the rear pair can be monitored? Not really necessary if the AB is working ok. Enjoy....

Good question, and I don't know the exact answer (as I just bought the amp, at a very good price so didn't really pay for the meter work). I believe it's just the front two tubes, and mostly for eye candy. like you said the auto bias board does it's job so not fully needed.

Bob's amps are a whole other world from the original Dynaco ST 70's. You have to remember that the originals are from the 60's or there abouts. They were designed to be simple and inexpensive, so compromises had to be used. They took many short cuts but the output transformers were the very good. Can't say the same about the power transformers, but they worked, just ran way too hot. I have restored or rebuilt hundreds of Dynaco amps and preamps and very few come into my shop working as they were designed. Many still work but don't meet most of the original specs. I have done conversions of the ST 70 with just about every board that has been designed for them. Bob's are extremely well thought out and executed. The only other one I have ever used that I think is worth using is Frank Van Alstine's update board. Frank has been modifying and updating Dyna stuff since the 70's and has shared most of the things he comes up with freely.

Bruce Brown

Tuninfork wrote:Bob's amps are a whole other world from the original Dynaco ST 70's. You have to remember that the originals are from the 60's or there abouts. They were designed to be simple and inexpensive, so compromises had to be used. They took many short cuts but the output transformers were the very good. Can't say the same about the power transformers, but they worked, just ran way too hot.  I have restored or rebuilt hundreds of Dynaco amps and preamps and very few come into my shop working as they were designed.  Many still work but don't meet most of the original specs. I have done conversions of the ST 70 with just about every board that has been designed for them. Bob's are extremely well thought out and executed. The only other one I have ever used that I think is worth using is Frank Van Alstine's update board. Frank has been modifying and updating Dyna stuff since the 70's and has shared most of the things he comes up with freely.

Bruce Brown

Thanks for the great info Bruce!

It is a shame the the SP9 is no longer available.  It is an awesome compensation for the variety of tonal differences I have found in the vinyl that I have collected over the past 50 years.

I had a friend who wanted a preamp built just like mine (https://dynacotubeaudio.forumotion.com/t4082-st-120-sp-9-ph16-and-power-sequencer).

markeby wrote:It is a shame the the SP9 is no longer available.  It is an awesome compensation for the variety of tonal differences I have found in the vinyl that I have collected over the past 50 years.

I had a friend who wanted a preamp built just like mine (https://dynacotubeaudio.forumotion.com/t4082-st-120-sp-9-ph16-and-power-sequencer).

Agree! With the PH12 phono I definitely need a little tone control for different albums to fine tune.