I want to build a ST-70 and will order a kit from either Bob Latino or Dynakitparts. Does anyone have an opinion on which would be better?
Both kits are out of stock now but should be back soon.
Let me apologize right now if I am starting a "which engine oil should I use" thread!
Thanks,
Frank
Both kits are out of stock now but should be back soon.
Let me apologize right now if I am starting a "which engine oil should I use" thread!
Thanks,
Frank
Dynakitparts version is close to the original, so for a slightly higher price the Latino version is better.
Remember that the tubes are additional, and EL-34 is the way to go. Also do this:
tube rectifier "yellow sheet" diode mod
Remember that the tubes are additional, and EL-34 is the way to go. Also do this:
tube rectifier "yellow sheet" diode mod
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While not nearly as scarce as the 7199, the 6GH8 is also out of production. AAMOF, all the useful pentode/triode types are NOS only. 🙁
If something comparatively close to the original is desired, consider building around Triode Electronics' board populated with 2X EF86s and an ECC99. The original signal topology is retained, while using in production types whose electrical performance is better than the devices found in the 7199.
If something comparatively close to the original is desired, consider building around Triode Electronics' board populated with 2X EF86s and an ECC99. The original signal topology is retained, while using in production types whose electrical performance is better than the devices found in the 7199.
Well, one thing your link showed me it that Bob is active on this forum! That is a big plus for customer support!
My local vintage hifi guy has a ST-70 for sale. I thought about buying it but when I started looking around at what it would cost to refurbish it I found these kits. I'm not too concerned with either price, I'm just trying to figure out the differences.
I planned on staying away from the 7199 version and it seems like 6GH8s are easily sourced but I see your point.
My local vintage hifi guy has a ST-70 for sale. I thought about buying it but when I started looking around at what it would cost to refurbish it I found these kits. I'm not too concerned with either price, I'm just trying to figure out the differences.
I planned on staying away from the 7199 version and it seems like 6GH8s are easily sourced but I see your point.
If it were me I woild buy one of the clone PCB's of the original, and build it up using one of the tp combo tubes from the later tube era such as the 6KR8. Cutting traces and jumpering are things I don't mind.
I can't say enough good about Bib Latino! Extraordinary support and I think great value for the money. I built his ST-120 and have. Been running the KT-120 tubes now for many years happily! Really a too notch guy.
Wow! Sad to hear the 6GH8A is out of production. It was the quietest pentode preamp tube I found while running the Audio Note ANK (rev e) design. Not sure if same result vs 6F2, 6U8A, 6EA8 in the Dynaco design. 6GH8A currently still available thru retail vendors, though.
Link below compares these tubes in ST70.
Jim
Replacing 7199 With 6GH8 And Comparing THD In A Dynaco ST-70 Vacuum Tube Amplifier - YouTube
I am not aware of any triod-pentode still in production. That said, there is no shortage of these, 6GH8, 6BL8 6U8 ECF80 ECF82 and others . All of the above
can be used in a Dynaco ST70 using an adapter plug.
I have compared several of these in a Dynaco SCA35 :
http://n.manet.nu/tubedoc/sca35-7199-alternative.pdf
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Do you have a schematic of his all-triode boards? Particularly the mono driver. I don't need circuit values, just the topology. I'd like to buy some of his boards for a project if they are close to what I need.
Here's their description:
Our driver circuit is a modern all triode driver design, for totally neutral uncolored sound.
One half of the first tube is used for each channel as a voltage amplifier.
One each of the other tubes is used per channel as a combined phase splitter/driver
in a long-tailed pair configuration. 13 db total loop feedback is used.
Our driver circuit is a modern all triode driver design, for totally neutral uncolored sound.
One half of the first tube is used for each channel as a voltage amplifier.
One each of the other tubes is used per channel as a combined phase splitter/driver
in a long-tailed pair configuration. 13 db total loop feedback is used.
The schematics is propetary. You will get a copy when purchasing an amp.
It is however a quite run-of-the mill design using ccs in the LTP splitter.
Hmmm,
Sounds to me as if front end dual triode design of Dynaco's ST35 has been 'adapted'
Jim
Concur. I also went with Bob Latino St-70 and dont desire anther tube amp. Bob Latino responds to emails or forum threads very quickly.
Erhard audio is another good shop for a kit.
I use their 6SN7 board in one of my ST-70’s and it’s my favorite of my 3 st-70’s
I use their 6SN7 board in one of my ST-70’s and it’s my favorite of my 3 st-70’s
Now that I've check out Bob's site I can't decide on the 70 or 120! I'll be driving Klipsch Heresy or Forte speakers so I don't need the higher output but the 120 really looks cool!
Both of those Klipsch models are supposed to be 99 dB. sensitive. Even in a large listening space, 35 WPC is overkill. A ST-35 "knock off" has more power than necessary, costs less, and (arguably) is built around the best O/P "iron" of the Dyna group.