AudioNervosa

Systemic Development => Amplification and Preamplification => Topic started by: TopRound‎ on November 26, 2022, 02:07:31 PM

Title: WTB Dynaco st 70
Post by: TopRound‎ 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
Title: Re: WTB Dynaco st 70
Post by: ejk 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

Title: Re: WTB Dynaco st 70
Post by: steve 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
Title: Re: WTB Dynaco st 70
Post by: ejk 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)
Title: Re: WTB Dynaco st 70
Post by: TopRound‎ 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
Title: Re: WTB Dynaco st 70
Post by: mresseguie 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
Title: Re: WTB Dynaco st 70
Post by: TopRound‎ 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!
Title: Re: WTB Dynaco st 70
Post by: TopRound‎ 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
Title: Re: WTB Dynaco st 70
Post by: Barry (NJ) 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 ;)
Title: Re: WTB Dynaco st 70
Post by: shadowlight on November 30, 2022, 12:31:00 PM
https://www.hifishark.com/search?q=dynaco+st70
Title: Re: WTB Dynaco st 70
Post by: TopRound‎ 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
Title: Re: WTB Dynaco st 70
Post by: TopRound‎ 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
Title: Re: WTB Dynaco st 70
Post by: steve 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
Title: Re: WTB Dynaco st 70
Post by: ejk 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
Title: Re: WTB Dynaco st 70
Post by: mresseguie 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.
Title: Re: WTB Dynaco st 70
Post by: TopRound‎ on November 30, 2022, 04:40:31 PM
I,m not Jewish but if I was and I was getting married, I would ask the rabbi if it was OK to smash an el34 instead of a glass!

The Ifi phono pre is very good , I bought one for my son and I think it sounds great.
That SW1X gear intrigues me very much. I had heard a couple AudioNote Dac kits and they sounded great, these SW1X things look like those kits reimagined in a new chassis, and new price. I could be wrong. I hope not as I am buying a couple AudioNote kits for my son to build so I am hoping they are as good or close to the SW1x stuff.

mike
Title: Re: WTB Dynaco st 70
Post by: P.I. on November 30, 2022, 10:29:59 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.
Sucks to be you with all of those choices!  :rofl:  :thumb:
Title: Re: WTB Dynaco st 70
Post by: Nick B on December 01, 2022, 01:03:50 AM
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.

Wow, dac mania! Having choices is good 🎶