Author Topic: WTB Dynaco st 70  (Read 5604 times)

Offline TopRound‎

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WTB Dynaco st 70
« on: November 26, 2022, 02:07:31 PM »
Looking for a Dynaco ST 70 if any available , broke is fine(preferred) as its going to be fully restored.
The monos would be great too...

thanks in advance


mike
System: Nothing....gave it all up, but building a few things for my kids...vinyl, tubes and Gan Fet!

Offline ejk

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Re: WTB Dynaco st 70
« Reply #1 on: November 26, 2022, 10:39:49 PM »
Looking for a Dynaco ST 70 if any available , broke is fine(preferred) as its going to be fully restored.
The monos would be great too...

thanks in advance


mike

https://www.usaudiomart.com/search.php?keywords=dynaco

I would just go with this.

https://www.china-hifi-audio.com/willsenton-tube-amplifier-c-77/willsenton-r8-kt88el34-x4-tube-integrated-amp-power-amplifier-headphone-p-2268

Aric Audio Super 6SN7 Line, Orchard Audio Starkrimson Ultra, Quicksilver Mid Monos, Lumin U2 Mini, Denafrips Pontus II 12th-1,Denafrips Iris DDC, Spatial Audio M3 Saphire, Hapa Audio Interconnects, TWL power cords, TWL speaker cables, Wireworld USB, i2s.

Offline steve

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Re: WTB Dynaco st 70
« Reply #2 on: November 28, 2022, 04:15:56 PM »
No mention of 120vac in specs nor channel separation. I would stick with the ST-70
and back to original.

If you want improved, upgraded sound, might check out SE-70, 3rd modification by
Pro Musica from Champaign (not Chicago). Even the second addition is quite good.

cheers

steve
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline ejk

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Re: WTB Dynaco st 70
« Reply #3 on: November 29, 2022, 12:53:31 AM »
No mention of 120vac in specs nor channel separation. I would stick with the ST-70
and back to original.

If you want improved, upgraded sound, might check out SE-70, 3rd modification by
Pro Musica from Champaign (not Chicago). Even the second addition is quite good.

cheers

steve

Comes in 120v

Have one since the summer. Mike has heard it

Features
Pure hand-made, the whole machine is welded with scaffolding.
Use a square power transformer specially developed for this machine.
The output transformer uses two high quality wideband EI output transformers.
The voltage amplification and boost stage uses a 6SN7 for power supply filtering.
The voltage amplification stage and the push stage use two pairs of 6SL7 and 6SN7 tubes, respectively.
The rear stage uses four KT88/6550/EL34 tubes for class AB single-ended power amplification.
Triode and ultra-linear selection are available.
External independent BIAS-ADJ current display header.
External EL34/KT88 tube selection function, easy to replace different types of tubes, adding endless fun.
Infrared full-featured remote control.
Use thick silver plated signal leads.
With pure post-level function, it can be connected to independent preamplifier signal input.
Power on mute delay function (about 30 seconds).
Select Japanese ALPS high-end motor potentiometer.
Easy-to-install plug-in tube shield.

Product parameters:
Frequency effect: 10Hz 40kHz (+/-0.5db)
Total harmonic distortion: 1% (1kHz)
Signal to noise ratio: 91dB
Input sensitivity: 380mv (when Integrated amp input) 820mv (when pure power amp input)
Input impedance: 100KΩ
Output impedance: 4Ω, 8Ω
Power supply voltage: 230V 5% (50Hz) ~ 115V 5% (50Hz)
Machine volume (400*200*390) (W*H*D) mm
Use vacuum tube: 6SN7*3.6SL7*2.KT88*4/6550EH*4/EL34*4
Power consumption: 310W
Net weight: 26kg -90%
Rated output power:
25W+25W (RMS triode working state)
45W+45W (RMS ultra linear working state) (KT88)
25W+25W (RMS triode working state)
40W+40W (RMS ultra linear working state) (EL34)
Aric Audio Super 6SN7 Line, Orchard Audio Starkrimson Ultra, Quicksilver Mid Monos, Lumin U2 Mini, Denafrips Pontus II 12th-1,Denafrips Iris DDC, Spatial Audio M3 Saphire, Hapa Audio Interconnects, TWL power cords, TWL speaker cables, Wireworld USB, i2s.

Offline TopRound‎

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Re: WTB Dynaco st 70
« Reply #4 on: November 29, 2022, 02:49:06 AM »
The Wellsington was very good! It would give most tube amps a run for their money.
Only reason I want the Dynaco is I want to do a vintage dynaco amp/pre/speaker combo.
The hardest thing to find in audio is synergy, and the st 70 with the Pas3 and dynaco A 25 speakers synergize extremely well.
All for very little money. They are simple designs that are easy to upgrade(need) and the upgrades yield huge improvements.
And its cheap.
Going to resurrect one of my turntables and play some of the thousands of records I have.
Fun little project
System: Nothing....gave it all up, but building a few things for my kids...vinyl, tubes and Gan Fet!

Offline mresseguie

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Re: WTB Dynaco st 70
« Reply #5 on: November 29, 2022, 07:10:42 AM »
I've got a set of tubes for the ST-70 that I could sell inexpensively if you're interested. The only caveat is that you have to wait for about six months until after I return to the US.

How did I end up with the tubes but not the amp, you ask? Well, I bought a used ST-70 from an AC member and used it intermittently for a couple months before boxing it up before I disappeared across the Pacific Ocean. After I returned home, I ended up selling it to someone else, but I couldn't find the tubes. Months later, I discovered where I had secreted the tubes, but the buyer didn't need them. They have sat in a box for nearly three years waiting for me to send them along to someone new. :thumb:

Michael
Daedalus Audio Apollos; Fritz Loudspeakers LS/5-R
SW1X NOS DAC III BAL/SPL; Holo Spring3 KTE
Don Sachs Model 2 preamp
Don Sachs dual mono 300b; Nuprime Evolution STA
Hapa loom
PI Audio UberBUSS, DigiBUSS, Uber-MiniBUS

Offline TopRound‎

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Re: WTB Dynaco st 70
« Reply #6 on: November 29, 2022, 07:56:00 PM »
well michael while you were secreted away fighting foreign wars  to save the planet I was waiting for you to find those magic el34 tubes I need for the dynaco amp I do not have yet. It seems like synergy in reverse, and I like that!
I will wait the six months for you to come back safe and sound and I may buy those tubes for the amp that I may buy as well
and if I do not and you sell them to someone else or use them in a jewish wedding ceremony and smash them under your shoe....well that is fine too! If i win the lottery I will remarry my wife and smash a 300b western electric tube under my loafers, even though I am not Jewish , I find the tradition ....fun! and my wife will wonder if remarrying to me was (is) a good idea.   come home soon......we need you

Mike

BTW my wife says she hates tubes, that means they are good!
System: Nothing....gave it all up, but building a few things for my kids...vinyl, tubes and Gan Fet!

Offline TopRound‎

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Re: WTB Dynaco st 70
« Reply #7 on: November 29, 2022, 08:00:42 PM »
BTW , I have heard the Sw1x phono and was extremely impressed
that you have the Dac makes me take off my hat(reveal my thinning hair) to you good sir!
Seems like gussied up AudioNoteKit stuff but done real well

Mike
System: Nothing....gave it all up, but building a few things for my kids...vinyl, tubes and Gan Fet!

Offline Barry (NJ)

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Re: WTB Dynaco st 70
« Reply #8 on: November 30, 2022, 11:51:26 AM »
The Wellsington was very good! It would give most tube amps a run for their money.
Only reason I want the Dynaco is I want to do a vintage dynaco amp/pre/speaker combo.
The hardest thing to find in audio is synergy, and the st 70 with the Pas3 and dynaco A 25 speakers synergize extremely well.
All for very little money. They are simple designs that are easy to upgrade(need) and the upgrades yield huge improvements.
And its cheap.
Going to resurrect one of my turntables and play some of the thousands of records I have.
Fun little project

Welcome back Mike!

Keep it sane and manageable ;)
Happiness is when your system overcomes your nervosa ;) 
So much media, so little time... My Media Room...

Offline shadowlight

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Re: WTB Dynaco st 70
« Reply #9 on: November 30, 2022, 12:31:00 PM »

Offline TopRound‎

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Re: WTB Dynaco st 70
« Reply #10 on: November 30, 2022, 01:45:44 PM »
Barry thanks for having me back

Sanity in an insane hobby...hmmmm

I will try to manage

thanks
System: Nothing....gave it all up, but building a few things for my kids...vinyl, tubes and Gan Fet!

Offline TopRound‎

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Re: WTB Dynaco st 70
« Reply #11 on: November 30, 2022, 01:51:59 PM »
Deepak,
Thanks for the ebay listings. Prices are ridiculous for these things these days, looking for a cheap one that needs work as its going to be rebuilt basically. Or I may hold out for a el 34 kit for my son to build.

Thanks
Mike
System: Nothing....gave it all up, but building a few things for my kids...vinyl, tubes and Gan Fet!

Offline steve

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Re: WTB Dynaco st 70
« Reply #12 on: November 30, 2022, 02:59:44 PM »
No mention of 120vac in specs nor channel separation. I would stick with the ST-70
and back to original.

If you want improved, upgraded sound, might check out SE-70, 3rd modification by
Pro Musica from Champaign (not Chicago). Even the second addition is quite good.

cheers

steve

Comes in 120v

Have one since the summer. Mike has heard it

Features
Pure hand-made, the whole machine is welded with scaffolding.
Use a square power transformer specially developed for this machine.
The output transformer uses two high quality wideband EI output transformers.
The voltage amplification and boost stage uses a 6SN7 for power supply filtering.
The voltage amplification stage and the push stage use two pairs of 6SL7 and 6SN7 tubes, respectively.
The rear stage uses four KT88/6550/EL34 tubes for class AB single-ended power amplification.
Triode and ultra-linear selection are available.
External independent BIAS-ADJ current display header.
External EL34/KT88 tube selection function, easy to replace different types of tubes, adding endless fun.
Infrared full-featured remote control.
Use thick silver plated signal leads.
With pure post-level function, it can be connected to independent preamplifier signal input.
Power on mute delay function (about 30 seconds).
Select Japanese ALPS high-end motor potentiometer.
Easy-to-install plug-in tube shield.

Product parameters:
Frequency effect: 10Hz 40kHz (+/-0.5db)
Total harmonic distortion: 1% (1kHz)
Signal to noise ratio: 91dB
Input sensitivity: 380mv (when Integrated amp input) 820mv (when pure power amp input)
Input impedance: 100KΩ
Output impedance: 4Ω, 8Ω
Power supply voltage: 230V 5% (50Hz) ~ 115V 5% (50Hz)
Machine volume (400*200*390) (W*H*D) mm
Use vacuum tube: 6SN7*3.6SL7*2.KT88*4/6550EH*4/EL34*4
Power consumption: 310W
Net weight: 26kg -90%
Rated output power:
25W+25W (RMS triode working state)
45W+45W (RMS ultra linear working state) (KT88)
25W+25W (RMS triode working state)
40W+40W (RMS ultra linear working state) (EL34)

Thanks Evan.
Now I see it at the very bottom. Above that, "certificate" it only says 220-240 volts 50hz  280 watts.
Folks, make sure you read the very bottom with all the specs as Evan indicates.

Is the AC voltage consumer switchable or factory set Evan?

A correction to the "features" if I may. For 40-45 watts output power/wattage, would require push pull output.
Single ended operation would require Class A, not AB, with generally much higher distortion figures.

cheers

steve
« Last Edit: November 30, 2022, 03:18:41 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline ejk

  • Obsessively Audiophilic
  • ****
  • Posts: 660
  • Did I say no dropouts ?
Re: WTB Dynaco st 70
« Reply #13 on: November 30, 2022, 03:30:51 PM »
No mention of 120vac in specs nor channel separation. I would stick with the ST-70
and back to original.

If you want improved, upgraded sound, might check out SE-70, 3rd modification by
Pro Musica from Champaign (not Chicago). Even the second addition is quite good.

cheers

steve

Comes in 120v

Have one since the summer. Mike has heard it

Features
Pure hand-made, the whole machine is welded with scaffolding.
Use a square power transformer specially developed for this machine.
The output transformer uses two high quality wideband EI output transformers.
The voltage amplification and boost stage uses a 6SN7 for power supply filtering.
The voltage amplification stage and the push stage use two pairs of 6SL7 and 6SN7 tubes, respectively.
The rear stage uses four KT88/6550/EL34 tubes for class AB single-ended power amplification.
Triode and ultra-linear selection are available.
External independent BIAS-ADJ current display header.
External EL34/KT88 tube selection function, easy to replace different types of tubes, adding endless fun.
Infrared full-featured remote control.
Use thick silver plated signal leads.
With pure post-level function, it can be connected to independent preamplifier signal input.
Power on mute delay function (about 30 seconds).
Select Japanese ALPS high-end motor potentiometer.
Easy-to-install plug-in tube shield.

Product parameters:
Frequency effect: 10Hz 40kHz (+/-0.5db)
Total harmonic distortion: 1% (1kHz)
Signal to noise ratio: 91dB
Input sensitivity: 380mv (when Integrated amp input) 820mv (when pure power amp input)
Input impedance: 100KΩ
Output impedance: 4Ω, 8Ω
Power supply voltage: 230V 5% (50Hz) ~ 115V 5% (50Hz)
Machine volume (400*200*390) (W*H*D) mm
Use vacuum tube: 6SN7*3.6SL7*2.KT88*4/6550EH*4/EL34*4
Power consumption: 310W
Net weight: 26kg -90%
Rated output power:
25W+25W (RMS triode working state)
45W+45W (RMS ultra linear working state) (KT88)
25W+25W (RMS triode working state)
40W+40W (RMS ultra linear working state) (EL34)

Thanks Evan.
Now I see it at the very bottom. Above that, "certificate" it only says 220-240 volts 50hz  280 watts.
Folks, make sure you read the very bottom with all the specs as Evan indicates.

Is the AC voltage consumer switchable or factory set Evan?

A correction to the "features" if I may. For 40-45 watts output power/wattage, would require push pull output.
Single ended operation would require Class A, not AB, with generally much higher distortion figures.

cheers

steve

Factory set
Aric Audio Super 6SN7 Line, Orchard Audio Starkrimson Ultra, Quicksilver Mid Monos, Lumin U2 Mini, Denafrips Pontus II 12th-1,Denafrips Iris DDC, Spatial Audio M3 Saphire, Hapa Audio Interconnects, TWL power cords, TWL speaker cables, Wireworld USB, i2s.

Offline mresseguie

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  • Posts: 500
Re: WTB Dynaco st 70
« Reply #14 on: November 30, 2022, 04:04:58 PM »
well michael while you were secreted away fighting foreign wars  to save the planet I was waiting for you to find those magic el34 tubes I need for the dynaco amp I do not have yet. It seems like synergy in reverse, and I like that!
I will wait the six months for you to come back safe and sound and I may buy those tubes for the amp that I may buy as well
and if I do not and you sell them to someone else or use them in a jewish wedding ceremony and smash them under your shoe....well that is fine too! If i win the lottery I will remarry my wife and smash a 300b western electric tube under my loafers, even though I am not Jewish , I find the tradition ....fun! and my wife will wonder if remarrying to me was (is) a good idea.   come home soon......we need you

Mike

BTW my wife says she hates tubes, that means they are good!

That's an interesting note about Jewish weddings. I've never attended one, but I do recall reading that they smash something under their feet. Are chalices or glasses the norm? Does anyone actually use tubes? Am I proving myself naive?  :D

BTW , I have heard the Sw1x phono and was extremely impressed
that you have the Dac makes me take off my hat(reveal my thinning hair) to you good sir!
Seems like gussied up AudioNoteKit stuff but done real well

Mike

I've often wondered about Slawa's phono pres, but with just 35 LPs to my name and a cheap used TT, my needs are satisfied by an inexpensive iFi phono pre.

After looking at the gear list in my signature, I realized I haven't changed it to reflect a change from about 2 months ago. As much as I love the DAC III+, I'd sometimes wondered what the DAC III Balanced (or even the DAC IV) sounds like, but figured I'd never find out thanks to their high cost. [The DAC III BAL retails for ~$13,200 plus shipping.] A nice gentleman in Orange County, CA placed his barely used DAC III BAL/SPL model in an Agon ad, and I happened to notice it after just a few hours of his placing the ad. His asking price indicated there was an issue or that it was a fake ad, so I hesitated for all of a few hours. I contacted him to see if he was real, and after a couple of conversations, I determined he was real. Anyway, I made an impulse buy because <in my mind> I would never find a great deal like this again. I'm now the proud <and somewhat stunned> owner of the DAC III BAL/SPL model.

And yes, I'd already ordered a Holo Spring3 KTE w/vc which was delivered just a week or two after my new SW1X DAC was delivered.  :drool: :rofl: :shock: I'm up to my eyeballs in wonderful sounding DACs.

The new DAC is so amazing that it makes its little brother sound flat and lifeless.  :shock: That was a shock because little brother sounds (sounded) wonderful in my system before big brother arrived.
Daedalus Audio Apollos; Fritz Loudspeakers LS/5-R
SW1X NOS DAC III BAL/SPL; Holo Spring3 KTE
Don Sachs Model 2 preamp
Don Sachs dual mono 300b; Nuprime Evolution STA
Hapa loom
PI Audio UberBUSS, DigiBUSS, Uber-MiniBUS