[jaylevine]

After several years of back and forth I'm finally dipping my toes in the tube ocean.

Purchased a VTA ST120 kit from Bob at tubes4hifi.com

Great reviews, looks like the kit is solid in all ways (updated circuitry and parts, better fittings etc). Only downside is the Dynaco platform is plug ugly IMHO.

Starting out with Bob's optional tube set Sovtek 6550WE, 3 12AU7, upgraded caps, 21 step attenuator  and and a gz43/5AR4 rectifier. Will run the unit without a pre-amp since my only source is a Bryston DAC and it puts out tons voltage from the unbalanced outputs.

More to come-- maybe I'll post build pictures as I get rolling this weekend (pun intended).

[rollo]

Have fun. What speakers are you mating the amp with ?

charles

[mresseguie]

VTA ST120.... Excellent choice!

I suspect you'll be mighty pleased with your decision. Enjoy!

Remember to post your impressions once it's hooked up and playing.

Michael

[opnly bafld]

the Dynaco platform is plug ugly IMHO.

+1

[jaylevine]

Have fun. What speakers are you mating the amp with ?

charles

I have a pair of Legacy Studio HD monitors. 93db at 4ohms. I only do near-field listening in a small room (10x12) with a dedicated seating position. The ST120 will drive these just fine.

I even spent some time with an SPL meter this past weekend to get a sense what my actual listening levels were at medium-high for representative music--hardly ever breaks 65db and on occasion cracks 70db. Plus my tastes run to vocals, piano, traditional jazz, and acoustic so not a lot of dynamic range or deep thunderous bass in my playing lists.

[jaylevine]

+1

I've been looking at what mods people do with chassis and layout. A lot of creative folks out there with woodworking and CNC skills I will never acquire. One thing I might do however is remove the bias taps off the front panel to a custom made plate somewhere either sitting on top the drive board, where the bias adjustment pots are located, or leave them in front but replace the tube sockets with something 20th century.

I plan on leaving the inputs on the front--Bob suggests it is risky to move them into the chassis to reach the rear panel since they might pick up noise.

My real beef with the looks are more to do with the stainless chassis. I almost prefer dull brushed metal. Before I start the build tomorrow night I'm going to paint the chassis a nice semi-gloss black to better accent the glowing tubes

[dB Cooper]

Use something like Krylon Hi-Temp... That chassis is going to be hot. Even better would be powdercoating

[dB Cooper]

Only downside is the Dynaco platform is plug ugly IMHO.

Almost 60-year-old budget design= butt ugly. For some reason front connections were not unconmmon in that era.
I was unfamiliar with this ST70-on-steroids design.... interesting. There have been more upgrades, modifications, and derivations of the ST70 than ay other amp in history.

[jaylevine]

I contacted Bob at VTA about the paint. He assured me the chassis temp never exceeds 85f or so. The only thing he recommends for high temp is if you paint the power transformer. Even that never exceeds 175f and most paint will do OK up to 200f.

Jay

[FullRangeMan]

I contacted Bob at VTA about the paint. He assured me the chassis temp never exceeds 85f or so. The only thing he recommends for high temp is if you paint the power transformer. Even that never exceeds 175f and most paint will do OK up to 200f.

Jay

In what room temperature?

[jaylevine]

ambient around 78f on average.

[mick wolfe]

I've had a Latino ST70 for years. Punches WAY above its price point. My friend has a Latino ST120 and I can tell you, it's superb as well.  FWIW, in the ST120, we both prefered the extra punch when a solid state Weber Copper Cap is used in place of the 5AR4. Your call here. He's currently using KT120's in his amp, but lots of choices here and some great NOS options with the small signal tubes. As a real bonus for us, one of Bob's recommended techicians lives about 3 miles from my house here in Tucson. I believe he builds the Latino amps that are ordered as "fully assembled" as well. This would apply to amps that are shipped west of the Mississippi.

[jaylevine]

Almost 60-year-old budget design= butt ugly. For some reason front connections were not unconmmon in that era.
I was unfamiliar with this ST70-on-steroids design.... interesting. There have been more upgrades, modifications, and derivations of the ST70 than ay other amp in history.

Interesting you mention the old design. There is an interesting interview in Stereophile with Nelson Pass where he comments on the virtues of tubes, the simplicity of circuit design and their sonic signature, among others. https://www.stereophile.com/content/nelson-pass-circuit-topology-and-end-science

[jaylevine]

I've had a Latino ST70 for years. Punches WAY above its price point. My friend has a Latino ST120 and I can tell you, it's superb as well.  FWIW, in the ST120, we both prefered the extra punch when a solid state Weber Copper Cap is used in place of the 5AR4. Your call here. He's currently using KT120's in his amp, but lots of choices here and some great NOS options with the small signal tubes. As a real bonus for us, one of Bob's recommended techicians lives about 3 miles from my house here in Tucson. I believe he builds the Latino amps that are ordered as "fully assembled" as well. This would apply to amps that are shipped west of the Mississippi.

Thanks! I thought about the Weber rectifier but I didn't opt for the circuit startup delay option that they offer. Bob sends out somewhat confusing messages on this, i.e. If you need the circuit startup delay in place with the Weber or not. In some posts he states it is not needed since the Weber has some delay before the heater voltage comes on, but on his site he recommends the option if your going to use a solid-state rectifier. Since I'm driving moderately efficent speakers not too concerned with needing the extra umph, but if the rectifier tube goes, as I've heard they have a tendency to do, I'll probably opt for the Weber as a replacement.

[Wind Chaser]

Interesting you mention the old design. There is an interesting interview in Stereophile with Nelson Pass where he comments on the virtues of tubes, the simplicity of circuit design and their sonic signature, among others. https://www.stereophile.com/content/nelson-pass-circuit-topology-and-end-science

That was a great read, thanks for posting.

[sabciu]

I have a Pair of Bob's M-125 Mono Blocks and they are Glorious! Very satisfied with what I am hearing 

I did the Piano Finish Sides on them myself.

[mick wolfe]

Great looking amp(s) 

[jaylevine]

I have a Pair of Bob's M-125 Mono Blocks and they are Glorious! Very satisfied with what I am hearing 

I did the Piano Finish Sides on them myself.

  amazing woodwork. I'd pay for a pair of those on my new rig....

[sabciu]

amazing woodwork. I'd pay for a pair of those on my new rig....

Thanks jaylevine!!

I did the finishing myself. I ordered some raw Curly / Tiger Maple for the sides and dyed them in Blood Red. I then finished them in a high gloss Piano Finish. I did the same for the Platforms they're sitting on. I ordered those Raw and did the finishing. I can tell you that I have a whole new level of appreciation for a rubbed out finish, and a whole new level of respect for the wood workers that do this type of finish like Jim Salk. It is very time consuming, and takes a lot of patience to get it right! It is also very easy to screw it up if you don't follow the recipe and become too anxious to finish it quickly. However, done right, you get to enjoy the result while it sits in front of you! 

[sabciu]

Great looking amp(s) 

Thanks mick Wolfe! Appreciate that and glad to be able to share it.