Have you seen this pic?

[midlife]

www.tubes4hifi.com Have you seen this picture? Anyone familiar with these Dynaco format amps?

[jcrobso]

I do remember them, I have Dynaco PAT4 pre amp.
The kits were very reasonably priced and had good specs.
The blue glow from the output tubes looks neat, but shows they are nearing the end of life.

[grumpy]

or a design with an unusually high B+ ... I have a musicman amp that does this with
fresh tubes , (700V, IIRC)

but keep in mind this is also a long-exposure photo that appears to have
had the color saturation cranked up for effect (much more likely to see the
"blue glow").

[midlife]

Are these Dynaco rebuilds good performers sonically? tubes4hifi also offers an "ST 120", 60wpc tube amp.

[jcrobso]

or a design with an unusually high B+ ... I have a musicman amp that does this with
fresh tubes , (700V, IIRC)

but keep in mind this is also a long-exposure photo that appears to have
had the color saturation cranked up for effect (much more likely to see the
"blue glow").

Also the tubes are not EL34s they look like older 6L6GB because of the shape of the glass.

[midlife]

Are they just nice to look at or are they a quality piece with good sonics?

[rgrjit8]

The ST 120 is a transistor amp.
I really liked the one I used to have.

[louped garouv]

Are they just nice to look at or are they a quality piece with good sonics?

i would say that it would depend on what you can manage to pick one up for....

i like my ST-70 for what it is...

[midlife]

i would say that it would depend on what you can manage to pick one up for....

i like my ST-70 for what it is...

I am considering their new kit build "ST-120" tube amp. It uses ST70 architechure and yields 60wpc. The cost is about 40% of what average Mac MC240s are going for. Was hoping to find some user comments.

[Allanvh5150]

Sorry to say that the blue glow is present in brand new tubes as well. It can be caused by three things under normal operation. The first and most usual is flouresence which is caused by the electrons bombarding the glass. Another cause is the presence of mercury in the tube or, on some tubes, can be an added gas in the tube. It is generally noted in power tubes and as Grumpy said, in tubes with a high plate voltage. I have a prototype amp using 211's that are using a plate voltage of 2Kv and they are as blue as I have ever seen. It only occurs of coursem when the plate voltage is applied.

Allan.

P.S. The "coke bottle" 6L6 is still available from some manufacturers.

[TonyM]

I've just completed the ST70 kit a week ago. The amp is not a rebuild, its all brand new parts. The power supply has added capacitance and a bigger transformer and the driver board is nothing like the original. Because of the larger transformer you have a lot more output tube options. The stainless steal chassis looks real good. If you like the look of the original ST70 you'll like this even more. I've never owned one before but it looks good in a Volkswagen functional sort of way.

I'm very pleased with it. It's the best amp I've used for driving my Altec Model 19s. I'm using it with an ARC LS25 preamp. The bass is a lot fuller than any of the transistor amps I've used with the 19, most of them made the speaker sound leaner than I thought it should. For my 4430s it might be a bit too full and the amp might be too small (which is probably why they came up with the 120). It's not the ultimate amp but it's a good match for a speaker that can get by on 35 watts of tube power. For a 19 that's plenty loud. On top of that the amp is pretty quiet.

Bob Latino who sells these seems to have no problem answering any questions by email fairly quickly. He's very much an expert with these amps as far as what works and what doesn't. I had no problems assembling the amp and it fired right up first time and has been flawless ever since. It's not real sophisticated but it doesn't need to be.

I imagine the ST120 is just more of the same.

[SMKSoundPro]

I have Dynaco pieces and parts and I played the game on ebay when I was more flush. Now my Mark III's with their Genelecs are sitting in boxes on a really strong shelf waiting for a day...

when I say I am done with these! I have been hauling them around for thirty years. They both work very well, and they are okay. I guess when I joined this forum back 2005, something here clicked, and I just can't get enough of a really good solid state smp to power all of the JBL options I now have.

Don't get me wrong. I understand the tube thing, I really do. And I service some tube type gear that comes through my hands to the best of my ability. Its just that, wow, sometimes a good smack from big old Yamaha or Crown makes me jump more.

Please tell us more about this new Dyna st70, and more about your hi-fi, and your JBLs.
Scotty.

[hjames]

I've just completed the ST70 kit a week ago. The amp is not a rebuild, its all brand new parts. The power supply has added capacitance and a bigger transformer and the driver board is nothing like the original. Because of the larger transformer you have a lot more output tube options. The stainless steal chassis looks real good. If you like the look of the original ST70 you'll like this even more. I've never owned one before but it looks good in a Volkswagen functional sort of way.

I imagine the ST120 is just more of the same.

So - is that these folks?
http://www.tubes4hifi.com/bob

Wow, looks very nice!

[midlife]

[quote=hjames;277296]So - is that these folks?
http://www.tubes4hifi.com/bob

Yep, thats them

[TonyM]

I have Dynaco pieces and parts and I played the game on ebay when I was more flush. Now my Mark III's with their Genelecs are sitting in boxes on a really strong shelf waiting for a day...

when I say I am done with these! I have been hauling them around for thirty years. They both work very well, and they are okay. I guess when I joined this forum back 2005, something here clicked, and I just can't get enough of a really good solid state smp to power all of the JBL options I now have.

Don't get me wrong. I understand the tube thing, I really do. And I service some tube type gear that comes through my hands to the best of my ability. Its just that, wow, sometimes a good smack from big old Yamaha or Crown makes me jump more.

Please tell us more about this new Dyna st70, and more about your hi-fi, and your JBLs.
Scotty.

To be fair this is not the only ST70 kit out there. Triode Electronics has one and so does Dynakitparts (there may be others). As best as I can tell the biggest difference between the kits is in the driver board used. It looks like the Dynakitparts kit is truer to the original. The ones from Triode and Bob Latino use different driver boards and updated connectors. Triode also offers a couple of different driver boards or no board if you want to choose a different board, there are several out there. These things are like 5.0 Mustangs, everybody knows their limitations and everybody has a solution so there's plenty of room for experimentation. The Latino kit is the only ST70 I've owned or heard so I don't have any reference to any of the other versions. Just Google Dynaco ST70 and you'll get plenty of opinions on all of the variables. There are much bigger experts out there.

I've driven the Altec Model 19s with four other amps. I started with a Yamaha M80 and Carver C16 pre. I'd actually bought the speakers used looking to see if they sounded like old Altecs I'd heard when I was younger (A7 and 604 type speakers). They had less bass than I remembered but that up front presence that I loved at the time. I know that when I heard the 604s in the past they were driven by a Mac 275. I did some work with the speakers fixing the connectors and improving the wiring. I swapped the caps out for Solens and did what I could to dampen the horn. Everything helped but the basic characteristic remained which I thought was good. Somewhere along the line I upgraded the power amp to an Adcom GFA 5802 which sounded better but the basic balance of the speaker remained. Eventually these speakers got shuffled to a second system as they were replaced by a pair of Martin Logan Ascent i hybrids.

In the second system they met up with an old Heathkit AA100 I restored. This worked OK but the amp was bandwidth limited and a little noisy. There was always one problem or another with it. When the 4430s showed up a couple of years ago I drove them with a Pioneer receiver but I knew I needed a real amp for them. So I purchased a NAD C372 which seemed big enough for the 4430s (150 wpc) and had a second output to drive the Altecs. The NAD worked well for both. The 4430s sounded fuller than the Altecs with the same amp. I still liked the 19s but by now they've been shuffled off as system 3.

Now I'm a firm believer that accurate reproduction is a pipe dream. Everything has to be taken in its context. You may be able to build an HD TV that looks like your looking out a window but none of the windows in my house swoop and pan through space or go into a soft focus or extreme close up. My point being that your reproduction system has to match the state of the art for what you're listening to. I've seen remastered versions of the original Star Trek. What looked so wonderous and imaginitive in the 60's looks like plywood and flat paint brought to life with modern technology now. Sure the sets were really plywood and flat paint but that's not what anybody wants to see.

Where I'm going with that is that I've got three real good pairs of speakers that represent different visions and different times. A pair of Martin Logans driven by a Pass X350 and ARC Ref 2 (state of the art 2001). A pair of JBL 4430s driven by a NAD C372, a solid state bipolar amp of decent power (state of the art 1990 style). And then these Altec 19s that are so magical but just don't seem to have the balance they must of had with old electronics.

Lately I've been listening to a lot of music from the 60's and 50's and some even earlier. Stuff like Magic Sam, Junior Wells, etc. Some of these are simple recordings balanced to be played back on systems that were popular back then. My thought was to put together a system that could play these recordings back the way they were meant to. I've already done the restore an old amp thing but most classic amps are fairly expensive and you still need to take them apart and put them back together. These new kits update the old design and you only have to put them back together. I matched the ST70 to my old ARC LS25 for an all tube system. Bang, everything I liked about the Model 19 was still there but that lean bass came up full and punchy. Yeah it's old school but it works perfectly for what I wanted it to do.

I agree with you about the solid state amps. I've been using tube preamps for several years now but I've always felt that tubes couldn't provide the current and control that I thought I needed. I'm not about to give up my solid state amps but there are plenty of applications out there for tube power amps. It's that system synergy thing.