Jump to content

Cornin with Dynaco


_RIGGED_

Recommended Posts

A while back I had three pair of Dynaco Mark III (all 1975 vintage) with one pair using VTA boards (KT88 output tubes), another using the Curcio boards (EL34 output tubes) and the third using the Shannon Parks Poseidon boards (KT88 output tubes) from the DIYtube site.
I have a VTA board for my ST70, to replace the Curcio board previously installed. Construction is definitely better on the VTA board. I don't have all the parts I need, but it is on the 'finish this summer' list. I'm also hoping it's an improvement.

Bruce

Link to comment
Share on other sites

A while back I had three pair of Dynaco Mark III (all 1975 vintage) with one pair using VTA boards (KT88 output tubes), another using the Curcio boards (EL34 output tubes) and the third using the Shannon Parks Poseidon boards (KT88 output tubes) from the DIYtube site.
I have a VTA board for my ST70, to replace the Curcio board previously installed. Construction is definitely better on the VTA board. I don't have all the parts I need, but it is on the 'finish this summer' list. I'm also hoping it's an improvement.

Bruce

I think the VTA boards make for a very nice upgrade. I've also got an original Dynaco ST70 that I found in a nice audio pick a few years ago that I should earmark for a VTA board. I'm starting to have an embarrassement of audio wealth and a very thin wallet due to those 'good deals' and an inquiring mind that won't look away......

Here are a couple of pictures of my Dynaco with the Parks Audio Poseidon boards from the DIYtube site. I call them my 'rat rod' mono blocks.....

Dynaco - Poseidon - Paoli 1.jpg

Dynaco - Poseidon - Paoli 3.jpg

Edited by Fjd
Link to comment
Share on other sites

Over the years, I've heard so many things(warmth, plays well with horns etc..) about tubes and like the Beekster said, I just want to experience them in my home.

Ok, kind of an experiment then. Of course we can't predict what kind of sound qualities others will like, so I would take this on from a different angle - what's the most "tube'ish sound" you could try, which would best show off the tube qualities? What experiment will give you the greatest insight into how tubes differ from transistor amps? Then, if you don't like that, there wouldn't be much sense going forward with it. You would have heard the example of "good tubes" clearly.

To that end, I would begin with Single-Ended Pentode (SEP) amps that feature no feedback. I think they offer the best window into tubes that you can buy on a modest budget. The most common recommendation, and one I used to make all the time, is the old Dynaco Ultralinear amps, like the ST70, MKIII and SCA35. But, ultralinear amps aren't really that close to today's state of the art in tube amps. Yes, they are good, and yes you can get lots of watts per dollar, but watts per dollar isn't the best way to show the strength of tube amps. A classic Single-Ended Triode (SET) amp would probably cost more than some of the new SEPs, and so for that reason they would be my second recommendation if you can find one in your budget.

A typical SEP with no feedback and really good transformer and caps inside, will demonstrate the beauty of tubes very well. The fine grain, the exquisite detail, the openness and see through clarity is common to these amps. You compare this to your SS amp, and you will say, "Oh, now I get what this tube thing is all about." It will be very obvious.

The Dynaco and all the hundreds of "ultralinear clones" fall behind the SET, SEP, in the finer points of tube sound, but they do offer more power. And to be clear, "more power" was the exact driving force behind the design of the ultralinear amps. On acoustic suspension speakers, the ultralinear has a clear advantage over SET/SEP. The cool thing about horns is that it opened the door to these better sounding, but less powerful designs, like SET/SEP.

Thanks for the recommendations however it's full steam ahead with the ST70, yes, there is a winner of the two.

I decided to get Bob L's advice and much to my surprise, he said I should go with the lower priced ST70.

Sadly, they do not keep wired boxes in stock, it will take up to 3 weeks from the payment date.

I am SO excited, my very first tube amp! Perhaps down the road I'll give SET amps a shot who knows.

I'll post pictures and my thoughts later on.

Thanks again to everyone!

RIGGED

Congrats on your purchase!

I may have missed it but did you give any thoughts to what pre you'll be using?

-R

Almost at the purchasing stage, still waitin for the check to come in. Preamp,hmmm, whatever I get it has to be on the smaller side, since it has to all fit inside the antique thingamagig my wife likes.

On another note, Bob Latino is very easy to deal with-oh waitin is the hardest part!

RIGGED

Link to comment
Share on other sites

A while back I had three pair of Dynaco Mark III (all 1975 vintage) with one pair using VTA boards (KT88 output tubes), another using the Curcio boards (EL34 output tubes) and the third using the Shannon Parks Poseidon boards (KT88 output tubes) from the DIYtube site.
I have a VTA board for my ST70, to replace the Curcio board previously installed. Construction is definitely better on the VTA board. I don't have all the parts I need, but it is on the 'finish this summer' list. I'm also hoping it's an improvement.

Bruce

I think the VTA boards make for a very nice upgrade. I've also got an original Dynaco ST70 that I found in a nice audio pick a few years ago that I should earmark for a VTA board. I'm starting to have an embarrassement of audio wealth and a very thin wallet due to those 'good deals' and an inquiring mind that won't look away......

Here are a couple of pictures of my Dynaco with the Parks Audio Poseidon boards from the DIYtube site. I call them my 'rat rod' mono blocks.....

Dynaco - Poseidon - Paoli 1.jpg

Dynaco - Poseidon - Paoli 3.jpg

Black electrical tape, speaker wire and hot glue.

Rat amp with rattier wiring...do you plan on doing a different layout/rebuild?

Link to comment
Share on other sites

  • 2 weeks later...

Over the years, I've heard so many things(warmth, plays well with horns etc..) about tubes and like the Beekster said, I just want to experience them in my home.

Ok, kind of an experiment then. Of course we can't predict what kind of sound qualities others will like, so I would take this on from a different angle - what's the most "tube'ish sound" you could try, which would best show off the tube qualities? What experiment will give you the greatest insight into how tubes differ from transistor amps? Then, if you don't like that, there wouldn't be much sense going forward with it. You would have heard the example of "good tubes" clearly.

To that end, I would begin with Single-Ended Pentode (SEP) amps that feature no feedback. I think they offer the best window into tubes that you can buy on a modest budget. The most common recommendation, and one I used to make all the time, is the old Dynaco Ultralinear amps, like the ST70, MKIII and SCA35. But, ultralinear amps aren't really that close to today's state of the art in tube amps. Yes, they are good, and yes you can get lots of watts per dollar, but watts per dollar isn't the best way to show the strength of tube amps. A classic Single-Ended Triode (SET) amp would probably cost more than some of the new SEPs, and so for that reason they would be my second recommendation if you can find one in your budget.

A typical SEP with no feedback and really good transformer and caps inside, will demonstrate the beauty of tubes very well. The fine grain, the exquisite detail, the openness and see through clarity is common to these amps. You compare this to your SS amp, and you will say, "Oh, now I get what this tube thing is all about." It will be very obvious.

The Dynaco and all the hundreds of "ultralinear clones" fall behind the SET, SEP, in the finer points of tube sound, but they do offer more power. And to be clear, "more power" was the exact driving force behind the design of the ultralinear amps. On acoustic suspension speakers, the ultralinear has a clear advantage over SET/SEP. The cool thing about horns is that it opened the door to these better sounding, but less powerful designs, like SET/SEP.

Thanks for the recommendations however it's full steam ahead with the ST70, yes, there is a winner of the two.

I decided to get Bob L's advice and much to my surprise, he said I should go with the lower priced ST70.

Sadly, they do not keep wired boxes in stock, it will take up to 3 weeks from the payment date.

I am SO excited, my very first tube amp! Perhaps down the road I'll give SET amps a shot who knows.

I'll post pictures and my thoughts later on.

Thanks again to everyone!

RIGGED

Hi Rigged,

Have you checked with Bob that you could get ST120 with the Pentode (60 wpc)/Triode (30wpc) switch so you'll have option to your set up?

I got my ST120 from Bob last year and very happy with it till now. Mostly in the Triode mode (& using my Denon AVR), I listen to accoustic jazz/vocal & classical on my RF62 & don't notice any distortion (maybe because of some rolled-off?).

For the pop/rock, i switch it to Pentode mode which give me more "open" sound & found no distortion so far.

Best regards,

Jimmy

  • Like 1
Link to comment
Share on other sites

Preamp,hmmm, whatever I get it has to be on the smaller side, since it has to all fit inside the antique thingamagig my wife likes.
I can't remember you saying how many sources you will have, but if you can find a Juicy Music Audio Merlin preamp, you will find it small in size and excellent in sonics. It doesn't have a phono pre, but I have used a small external on to great satisfaction. It has two line ins, but you can add something else with the tape monitor input. It uses a single tube and is tube rectified. Barely gets warm.

Not made anymore and I don't see them come up for sale often, but superb!

Bruce

Link to comment
Share on other sites

If you are going the Latino kit path go ST70....its wattage 1 through 35 is much better the any of the power coming out of the ST120....way too many compromises were built into squeezing 60 watts out of the same form factor chassis.

I'd actual suggest you take another kit route...buy a ST70 kit from Kevin at dynakitparts.com and have him leave out the stock front end board. Then purchase the front end circuit board made by Shannon Parks. Much better design then the VTA that Latino utilized.

Edited by NOSValves
Link to comment
Share on other sites

Latino kits are excellent. My thoughts differ a bit from Craig's: I would suggest choosing the kit you want first and building it exactly as designed. If you start tweaking before you have even heard it, there is no way of determining whether the modifications you employ are actually better than what was there to begin with. The only advice that you should follow on what is ultimately good, better, or worse is what you hear with your very own ears. Use the stock kit and the included passive and active parts as a platform from which you can establish a baseline for comparison. If you end up making changes, make one at a time, comparing it to your baseline. If you make a change or selection of a part (cap, resistor, whatever -- as long as the values and power ratings are correct and thus safe for both you and the component) that someone else might not like, don't worry about it. Use what works best for you.

Link to comment
Share on other sites

Latino kits are excellent. My thoughts differ a bit from Craig's: I would suggest choosing the kit you want first and building it exactly as designed. If you start tweaking before you have even heard it, there is no way of determining whether the modifications you employ are actually better than what was there to begin with. The only advice that you should follow on what is ultimately good, better, or worse is what you hear with your very own ears. Use the stock kit and the included passive and active parts as a platform from which you can establish a baseline for comparison. If you end up making changes, make one at a time, comparing it to your baseline. If you make a change or selection of a part (cap, resistor, whatever -- as long as the values and power ratings are correct and thus safe for both you and the component) that someone else might not like, don't worry about it. Use what works best for you.

Wow that's a big surprise....

Link to comment
Share on other sites

  • 2 weeks later...
Sadly, they do not keep wired boxes in stock, it will take up to 3 weeks from the payment date.

When did the OP change to a kit? I assumed he was buying a finished one?

I decided to go ahead and get one already made. Due to a financial emergency, I was forced to buy one from the Bay, and it arrived today, sadly with the on/off switch broken! OYE!!!

So I decided to head to RAT Shack to buy a replacement, thing is, while I can do a decent job of solderin, I'm not sure how to wire the new switch.

The original was wired like this.

One side had a brown wire to fuse, the pin underneath was a black wire to the 120VAC

The other side had a black wire to the power supply, and the pin underneath a white wire to the 120VAC.

The original switch was a toggle, this one is a slide switch. The original is the one on the left.

The ole gut says to wire the same but I really want to make this thing sing tonight, so I figured I'd ask the pros.

HELP!!!!

post-30562-0-49120000-1403996977_thumb.j

Edited by _RIGGED_
Link to comment
Share on other sites

Sadly, they do not keep wired boxes in stock, it will take up to 3 weeks from the payment date.

When did the OP change to a kit? I assumed he was buying a finished one?

I decided to go ahead and get one already made. Due to a financial emergency, I was forced to buy one from the Bay, and it arrived today, sadly with the on/off switch broken! OYE!!!

So I decided to head to RAT Shack to buy a replacement, thing is, while I can do a decent job of solderin, I'm not sure how to wire the new switch.

The original was wired like this.

One side had a brown wire to fuse, the pin underneath was a black wire to the 120VAC

The other side had a black wire to the power supply, and the pin underneath a white wire to the 120VAC.

The original switch was a toggle, this one is a slide switch. The original is the one on the left.

The ole gut says to wire the same but I really want to make this thing sing tonight, so I figured I'd ask the pros.

HELP!!!!

If you need help with a dynaco; pose your question on tubes4hifi.com's forum, you'll likely get a response pretty quickly. People there are eager and knowledgeable.

Link to comment
Share on other sites

Tweet, Bruce and Mark,

I agree with all points. For the most part......

But isn't it music dependent? Playing acoustic jazz at 100db is different than playing electronica at 100db for example.

Listening to a 12wpc amp into super efficient horns....a thing of beauty.

BUT 100db of serious LF?

Plug in the insertion loss of a high part count network?

I detest floppy bass.

My ear tells me headroom is needed. Maybe not always but for the rest of your life :D

tc

Link to comment
Share on other sites

Sadly, they do not keep wired boxes in stock, it will take up to 3 weeks from the payment date.

When did the OP change to a kit? I assumed he was buying a finished one?

I decided to go ahead and get one already made. Due to a financial emergency, I was forced to buy one from the Bay, and it arrived today, sadly with the on/off switch broken! OYE!!!

So I decided to head to RAT Shack to buy a replacement, thing is, while I can do a decent job of solderin, I'm not sure how to wire the new switch.

The original was wired like this.

One side had a brown wire to fuse, the pin underneath was a black wire to the 120VAC

The other side had a black wire to the power supply, and the pin underneath a white wire to the 120VAC.

The original switch was a toggle, this one is a slide switch. The original is the one on the left.

The ole gut says to wire the same but I really want to make this thing sing tonight, so I figured I'd ask the pros.

HELP!!!!

If you need help with a dynaco; pose your question on tubes4hifi.com's forum, you'll likely get a response pretty quickly. People there are eager and knowledgeable.

After consulting with an electrician, I wired accordingly, much to my dismay, the right channel ain't workin.

Upon further investigation, the right terminal connector piece was broken internal like. I contacted the seller and he his sending a replacement, the cat has been awesome by that way. Man, it's killin me to have this wave and not be able to surf it.

And, I have an outta town trip comin up so, it will further delay my enjoyment, ah, what the heck, I've waited this long right?

RIGGED

Link to comment
Share on other sites

  • 2 weeks later...

Alrighty, time for a mini review.

Music

Diana Krall

Spyro Gyra

George Strait-I am from Texas after all.

Michael Buble Live

Annie Lennox

Simply Red

Evian to tap water sums it up, the clarity of the tubes is what struck me right away, as did the tamed down bass response. I mean, the bass was still there, just not as palpable. Another worry I had stuck in the crane was power, would the ST70 have enough ummph to suit my needs, the answer is YES! Will I rid my abode from SS, no! It's still a must for home theater and for the occasional rock concert but for easy listenin, I've been TUBED, hook line and sinker!

After spending a solid hour with the ST70, I did notice something was missing, the headache SS would give me, with the same decibles and set list. SS has become much like a drag race, awesome for a brief time period while tubes are more like a Nascar race if that makes sense.

Thanks to all of those who took time to opine on this matter, It is greatly appreciated fellas.

BTW the amp I purchased turned out to be a Latino, just not built by Bob.

RIGGED

post-30562-0-80740000-1405189894_thumb.j

Edited by _RIGGED_
  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...