• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Dynaco ST70 Reintroduced!

juno said:
I really wish the VTA had dual rectifiers. This one actually just moved to the top of my list, pending more info.
Click to expand...
Do you have a VTA ST-70 already? If so, I think you could retro-fit an SS power supply, or mount the other 5AR4 where the can capacitor is and fit new filter caps underneath. If not, you could talk to Roy Mottram about a custom mod.

The above are just DIY suggestions. It may well be better to get a new series 3.
 
Dandy said:
Do you have a VTA ST-70 already? If so, I think you could retro-fit an SS power supply, or mount the other 5AR4 where the can capacitor is and fit new filter caps underneath. If not, you could talk to Roy Mottram about a custom mod.

The above are just DIY suggestions. It may well be better to get a new series 3.
Click to expand...
No, I don't have one. Am considering one or else this new dynaco amp. I do like the triode/pentode switch on the VTA version....ill wait for some more reviews on the new one and email Bob &co about the vta
 
My Latino ST70 I chose not to wire it with the triode switches because I already have an AES Superamp that I built wired in triode and I have a 300B SE amp. The Ultravalve sure is a nice looking amp.
 
I think a 'shoot-out' between Latino's amp and this new one is rather an 'unfair' comparison. If you consider that Bob's amp was meant to 'emulate' the 'original', then to some extent it's going to have some of the same limitations that the original amp possessed. I mean let's face it, you can take two 'original' ST-70s and do a shoot-out between them ...... and one will probably sound a bit different than the other. ....... UNLESS.....you 'blue-print' them both! By that, I mean that if you go through them both and get ever single design detail 'to spec'...then they probably will both sound about the same. Even then, there could still be component differences that make one perform slightly differently than the other under certain conditions. Not to dwell on this, but consider two automobiles coming off the same assembly line one right after the other. Both identically the same models, identically equipped. Yet, one gets slightly better fuel economy while one will consistently beat the other in the 1/8th mile. One has less wind noise, one has rattle in the dash. You could shoot out two of these 'new' ST-70 Mk IIIs and probably hear some differences between the two.....or not. But if you didn't, maybe one's Power Transformer will shoot craps in 4 years while the other's will last for 50!!

Speaking of the 6GH8 driver tube, did anyone read that VanAlsteen article from about 1995 or so, where he did some extensive research bumping the 7199 performance against the 6GH8A.....and came away with results that in his opinion pronounced that 6GH8 as a BETTER tube than the 7199? If anyone remembers his driver board set up for the ST-70, it was perhaps one of the most complex of any in it's day. But, now with the CC devices applied, adding the IBAM pots, etc....the 'original' driver by Dynaco really has been revitalized to a point where I think these improvements are undeniable. However, as Gadget rather referred to above...... unless you put two 5AR4s into it somehow, it's still limited at the top end of it's performance capability by it's limited power supply design.....and perhaps even by the transformer's capability as well. Hopefully some, or most, of this is resolved in this new amp, as I think some of the newer Kit versions (including even the Dynakitparts version from Kevin Devany) have attempted to do. To me, this really boils down to: Do you want the 'old school' original looking unit......or, do you want to spend the extra money for the 'new' unit and get something more modern looking to perhaps go with some other 'new' equipment you might have in your system? I doubt very seriously that anyone buying one of these new units will take the time to 'A/B' it's performance against any other ST-70 version as part of their buying decision process. Just my opinion.... FWIW. WC
 
stinz said:
I am new to tubes but after reading the Absolute Sounds article on the ST-70 series 3 and seeing it priced at $1499 I decided to make the plunge pairing it with the Rogue Aduio RP-1 pre amp driving some DQ-10's the sound is wonderful and I'm very happy with it.
Click to expand...
do you have a link to that review? I could not find one on the ST-70-3
nice to hear from someone who has one! thanks
 
I think it is a fair comparison because they are all attempts at IMPROVING upon the original.

I am not concerned with blueprinting individual amps for a head to head comparison of supplier built amps. Otherwise I would need to order several blueprints from whatever manufacturer I decide on to pick an individual specimen.

I do not care much about what the chassis looks like at this point as I am more concerned about the sound. As far as I am concerned, they are all in the same ballpark. For what its worth, I do tend to prefer amps that look nice without a tube cage. I can live with the looks of all of them. Nothing I would reject on looks alone!

I think a head to head of all three would be a great thing. None of them have any options, other than the VTA. So I would say get all the upgrades and go with that for a comparison.

I was not suggesting an individual do this. More like a magazine, blog, etc.

I agree that the tube rectified models should have 2 rectifier tubes. I am not sure why this was not done.

I am currently leaning toward the new Dynaco, to be honest.

Wharfcreek said:
I think a 'shoot-out' between Latino's amp and this new one is rather an 'unfair' comparison. If you consider that Bob's amp was meant to 'emulate' the 'original', then to some extent it's going to have some of the same limitations that the original amp possessed. I mean let's face it, you can take two 'original' ST-70s and do a shoot-out between them ...... and one will probably sound a bit different than the other. ....... UNLESS.....you 'blue-print' them both! By that, I mean that if you go through them both and get ever single design detail 'to spec'...then they probably will both sound about the same. Even then, there could still be component differences that make one perform slightly differently than the other under certain conditions. Not to dwell on this, but consider two automobiles coming off the same assembly line one right after the other. Both identically the same models, identically equipped. Yet, one gets slightly better fuel economy while one will consistently beat the other in the 1/8th mile. One has less wind noise, one has rattle in the dash. You could shoot out two of these 'new' ST-70 Mk IIIs and probably hear some differences between the two.....or not. But if you didn't, maybe one's Power Transformer will shoot craps in 4 years while the other's will last for 50!!

Speaking of the 6GH8 driver tube, did anyone read that VanAlsteen article from about 1995 or so, where he did some extensive research bumping the 7199 performance against the 6GH8A.....and came away with results that in his opinion pronounced that 6GH8 as a BETTER tube than the 7199? If anyone remembers his driver board set up for the ST-70, it was perhaps one of the most complex of any in it's day. But, now with the CC devices applied, adding the IBAM pots, etc....the 'original' driver by Dynaco really has been revitalized to a point where I think these improvements are undeniable. However, as Gadget rather referred to above...... unless you put two 5AR4s into it somehow, it's still limited at the top end of it's performance capability by it's limited power supply design.....and perhaps even by the transformer's capability as well. Hopefully some, or most, of this is resolved in this new amp, as I think some of the newer Kit versions (including even the Dynakitparts version from Kevin Devany) have attempted to do. To me, this really boils down to: Do you want the 'old school' original looking unit......or, do you want to spend the extra money for the 'new' unit and get something more modern looking to perhaps go with some other 'new' equipment you might have in your system? I doubt very seriously that anyone buying one of these new units will take the time to 'A/B' it's performance against any other ST-70 version as part of their buying decision process. Just my opinion.... FWIW. WC
Click to expand...
 
I wanted to compare my ST70 Series 2 with a Latino VTA ST70 I just completed but my VTA went up in smoke before I had a chance to listen to it.
 
I'm currently listening to my series 2. Tomorrow I'll rotate my Cary Superamp back in, which I also built from a kit. This is my third kit built amp and the only one that I've had a problem with. I haven't found any wiring error. The choke smoked. Bob thinks it may be the quad cap. I've temporarily walked away from it. My Series 2 doesn't sound bad especially after I upgraded all the coupling caps but it doesn't quite approach my other two kit built amps.
 
I have the VTA70 and like it very much, but at 1499 I am still tempted to buy this new Dynaco. I think mostly for its very smart looks, but also for its sensible and useful features such as switchable output impedance, audio inputs on back, led bias set indicators, detachable power cord, dual attenuators, and Low cut filter options. I think what I would miss most, though, is the enjoyment of saying "I built my own amp". However, I might get over that if the new Dynaco sounds better than the VTA. My guess based on what I've read about the circuit, though, is that they will sound nearly identical. That said, I think a stand-off test between these two is both essential and inevitable if these two are to coexist.

I might also miss the triode/pentode switches. I definitely like my VTA70 better in triode mode (I guess Hafler would be disappointed in me). I might have to modify the new ST70 to add the same if I did get one. One thing for sure, this amp is going to be a serious competitor for the VTA offerings if it stays available at 1499. I can't imagine too many people electing to build the kit for 500 or so less even if it is a ton of fun. I hope to hear some comparative listening results soon. I kind of hope the VTA sounds better so I won't have to spend more money ;)
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom