Reply
 
Thread Tools Display Modes
  #1   Report Post  
Tubetwang
 
Posts: n/a
Default pre-amp for Dyna ST-70

built a passive pre-amp for my rebuilt ST-70 using a step attenuator.
Would an active pre-amp work better with the Dynaco?
Have the Foreplay in mind...
Thanks,
Twang
  #2   Report Post  
Jon Yaeger
 
Posts: n/a
Default

In my experience, things always go better with a little Foreplay.

;-)

From: (Tubetwang)
Organization:
http://groups.google.com/
Newsgroups: rec.audio.tubes
Date: 18 Jul 2003 09:01:53 -0700
Subject: pre-amp for Dyna ST-70

built a passive pre-amp for my rebuilt ST-70 using a step attenuator.
Would an active pre-amp work better with the Dynaco?
Have the Foreplay in mind...
Thanks,
Twang



  #3   Report Post  
Mikkel C. Simonsen
 
Posts: n/a
Default

Tubetwang wrote:

built a passive pre-amp for my rebuilt ST-70 using a step attenuator.
Would an active pre-amp work better with the Dynaco?


Can you play load enough with all your signal sources? If that's the
case you don't need a preamp, if you can't then you do need a preamp.

If you want a preamp as an "effect unit" to change the sound, that's a
different matter...

Best regards,

Mikkel C. Simonsen
  #4   Report Post  
Ronald
 
Posts: n/a
Default

Hi ,

If you want a preamp as an "effect unit" to change the sound, that's a
different matter...


It might be better tu upgrade the ST-70 then .....
Or even rebuild it just using the iron and a different topology ......
2A3 - PP might be an option ........

Ronald .



  #5   Report Post  
Ronald
 
Posts: n/a
Default

Hi ,

2A3 - PP might be an option ........


Why not 6B4G PP - they will fit in the original sockets. Ned Carlson has
made such an amp using the Sovtek 6B4G tubes as far as I remember...


OK , you're right , but the 2A3 might be better known .....
It's up to Tubetwang now to react ......
So we can help him better .

Regards ,

Ronald .




  #6   Report Post  
Mikkel C. Simonsen
 
Posts: n/a
Default

Ronald wrote:

Hi ,

If you want a preamp as an "effect unit" to change the sound, that's a
different matter...


It might be better tu upgrade the ST-70 then .....
Or even rebuild it just using the iron and a different topology ......
2A3 - PP might be an option ........


Why not 6B4G PP - they will fit in the original sockets. Ned Carlson has
made such an amp using the Sovtek 6B4G tubes as far as I remember...

Best regards,

Mikkel C. Simonsen
  #7   Report Post  
Tubetwang
 
Posts: n/a
Default

"Ronald" wrote in message ...
Hi ,

2A3 - PP might be an option ........


Why not 6B4G PP - they will fit in the original sockets. Ned Carlson has
made such an amp using the Sovtek 6B4G tubes as far as I remember...


OK , you're right , but the 2A3 might be better known .....
It's up to Tubetwang now to react ......
So we can help him better .

Regards ,

Ronald .



Thanks guys , you have answered well!

This ST70 has been rebuild with Ned's board and power supply and i am
very please with the sound of it with the Jensen Copper caps.

I had rebuild two other amps previously, namely Dyna (SCA35)and
Heatkit AA-151 using a stepped attenuator on each.
The soud was "blooming " quicker on those (1/4 turn).

I have to turn the volume 15 minutes more on the ST70 to get the same
sound.
So i was wondering...

It's working great so i'll enjoy it...
Thanks again!
Twang
  #8   Report Post  
Ronald
 
Posts: n/a
Default

I don't know the ST70 that good and don't know Ned's board at all ....
But if not already you can get some extra gain if the cathode resistors
are not by-passed yet ......
On the other hand this might add some colouring of the sound ......

"Tubetwang" schreef in bericht
om...
"Ronald" wrote in message

...
Hi ,

2A3 - PP might be an option ........

Why not 6B4G PP - they will fit in the original sockets. Ned Carlson

has
made such an amp using the Sovtek 6B4G tubes as far as I remember...


OK , you're right , but the 2A3 might be better known .....
It's up to Tubetwang now to react ......
So we can help him better .

Regards ,

Ronald .



Thanks guys , you have answered well!

This ST70 has been rebuild with Ned's board and power supply and i am
very please with the sound of it with the Jensen Copper caps.

I had rebuild two other amps previously, namely Dyna (SCA35)and
Heatkit AA-151 using a stepped attenuator on each.
The soud was "blooming " quicker on those (1/4 turn).

I have to turn the volume 15 minutes more on the ST70 to get the same
sound.
So i was wondering...

It's working great so i'll enjoy it...
Thanks again!
Twang



  #9   Report Post  
Jon Yaeger
 
Posts: n/a
Default

I've rebuilt a number for ST-70s using different pre-packaged mods. With
all due respects to Ned, the Welbourne Labs mod is the best I've heard so
far. I'm in the process of putting together my second Welbourne ST-70 (the
first was sold to a fellow who wanted it so bad he was willing to pay $700).

I've been working on a few tube pre-amps. The Van Alstine PAS mod was
frankly a disappointment. I've been looking at Patrick Turner's April 200
circuit and it looks most intriguing . . .

- Jon

From: "Ronald"
Organization: @Home Benelux
Newsgroups: rec.audio.tubes
Date: Sat, 19 Jul 2003 20:28:19 +0200
Subject: pre-amp for Dyna ST-70

Hi ,

2A3 - PP might be an option ........


Why not 6B4G PP - they will fit in the original sockets. Ned Carlson has
made such an amp using the Sovtek 6B4G tubes as far as I remember...


OK , you're right , but the 2A3 might be better known .....
It's up to Tubetwang now to react ......
So we can help him better .

Regards ,

Ronald .




Reply
Thread Tools
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT +1. The time now is 10:01 AM.

Powered by: vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AudioBanter.com.
The comments are property of their posters.
 

About Us

"It's about Audio and hi-fi"