Newbie to Tube Audio

[rockable]

I'm not a newbie by any means when it comes to Hi Fi equipment, as that has been a hobby for 40 years, off and on. Also, I've repaired and restored guitar amps, mostly Fender, for the past 4 years.

The tube bug got to gnawing on me recently to do a vintage tube Hi Fi system. After doing much research, the ST-70 looks like a really good place to start. I have a set of Large Advents that I'm going to use and, thus far, have not bought any more components.

I do have a few questions. Should I get a "stock" ST-70 and tune it back up to stock specs or should I mod it? Should I just put in a new driver board and use upgraded cap can or should I put a power supply board in as well? I'd like to have a good sounding system and there seems to be room for improvement. What mods are recommended here?

Regarding a preamp, should I buy a NAD, Lux or similar older Solid State preamp or should I mod a PAS to use with my system? I will play ipod, CDs and Vinyl through it. Will I give up some of the tube magic by using SS preamp?

Any other tips?

Thanks for your patience and your opinions. I'm looking forward to this project. If it's like others, it will just be the start. :)

[Slartibartfast]

I do have a few questions. Should I get a "stock" ST-70 and tune it back up to stock specs or should I mod it? Should I just put in a new driver board and use upgraded cap can or should I put a power supply board in as well? I'd like to have a good sounding system and there seems to be room for improvement. What mods are recommended here?

Regarding a preamp, should I buy a NAD, Lux or similar older Solid State preamp or should I mod a PAS to use with my system? I will play ipod, CDs and Vinyl through it. Will I give up some of the tube magic by using SS preamp?

I bought a used ST-70 and PAS preamp from ebay and modded them back to the original circuit. with new parts. If I were to do it now, I would buy a new kit from dynakit.com and install one of the many great driver boards available today.

As for the preamp, I would keep it a tube unit, but that's just me. Modding the PAS has been fun. There are plenty of changes to be made to make the original preamp sound better. dynaco-doctor.com has plenty of great new boards to make it even better.

[TomMcNally]

Hi and welcome to the diytube forum !

An ST-70 is a good way to get started, or build a new ST-70 with available "clone" transformers and new chassis, drive board etc.

If you get a vintage amp, and the driver board isn't falling apart, you can replace the caps and out of tolerance resistors, and replace the selenium rectifier and bias caps with silicon diode and new caps.

As far as the preamp ... a lot of us on here are using eBay'ed Adcom solid state preamps, which have a nice phono preamp, tuner and motorized pot-style remote control. They were very expensive new, but aren't all that much on the used market. A PAS us a lot of work and expense for little benefit.

Just my experience and opinion.

... tom

[rockable]

Which Adcom's have phono capability and remote and are recommended?

I like building kits, so a kit might me a good option on the ST-70. Whose kits/boards, etc. are recommended?

[TomMcNally]

There is a more definitive list if you use SEARCH here on the forum - but the Adcom GTP-500II is one I have two of ... has phono preamp, tuner, remote control - very nice and sounds great. Many of the remotes have been lost, broken or eaten by the dog - but many (not all) of the universal remotes will work most of the functions ... all that really matters to me is volume, and even my Tivo remote will work that.

[Ty_Bower]

Which Adcom's have phono capability and remote and are recommended?

There was quite a discussion on the Adcom pre's here:
http://www.diytube.com/phpBB2/viewtopic ... 06&start=9

[snitch56]

I recently built a ST70 from all new parts. Chassis was from dynakitparts.com, transformers are triode dynaclones, and the driver board is from DIYtube. Tubes are new Electro-Harmonix all around. For the power supply I stayed with the stock configuration using the upgraded 80/40/30/20 can cap from dynakitparts. Total cost of the project was around $900.00. I did use auricap’s on the board, used all stainless steel hardware and bought a cage from ebay which increased the overall cost of the project.

It’s a great sounding amp and it is hard for me to imagine a stock ST70 with “original iron” sounding better.

[ecir38]

Another nice solid state preamp with a good phono section is the Forte Model 2. Some of them have external power supplies. There are upgrades that can made to them if you search around. No remote.

example, no affiliation
http://tinyurl.com/48vqtu

You can get it cheaper if you have patience looking for one.

If I didn't have a tube line stage and tube phono stage already, this is what I would look for.

[rockable]

Thanks for the info and the link on the preamps. I guess having remote control on your preamp is like bringing tubes into the 21st century, huh! I've got no problems with that, as I'm as resistant to getting up to turn down the volume as the next guy.

I am thinking about just building an amp from kit, based on what I'm hearing. I'll come out about as good, maybe better, and have a new amp. Besides, I like building kits.

Does anyone have the "perfect" ST-70 kit or should I mix and match until I get what I THINK I want?

[TomMcNally]

I'd suggest you download and print the PDF manual for the diytube ST-70 board ... it all the info you need to put an amp together. You can get all of the small parts from Mouser Electronics, the tubes from any vendor you like, I'd suggest a chassis and transformers from Triode Electronics, and then either use an SDS Labs or CChong capacitor board. You can get all of the small hardware at a local store. It's an easy build and will sound great. There are guys here to help you if you need it too.

[rockable]

I know about all those other guys but where do I find out about CChong?

[kheper]

Thanks for the info and the link on the preamps. I guess having remote control on your preamp is like bringing tubes into the 21st century, huh! I've got no problems with that, as I'm as resistant to getting up to turn down the volume as the next guy.

I am thinking about just building an amp from kit, based on what I'm hearing. I'll come out about as good, maybe better, and have a new amp. Besides, I like building kits.

Does anyone have the "perfect" ST-70 kit or should I mix and match until I get what I THINK I want?

There is no 'perfect' kit. There is alot of subjectivity involved. The two currently available kits, which I know of are:
DYNAKIT's and Triode's.

The DYNAKIT package uses the old driver board. You would need put in about $75 more for a diytube board and parts.

$650.00

http://www.dynakitparts.com/store/product.aspx?id=2


The triode kit contains an upgraded driver board and cap board, but the kit is sold without tubes.

$585.00

http://store.triodestore.com/st70buildkit.html

[rockable]

The link for the diy board doesn't work.

[TomMcNally]

CChong sells various Dynaco related things on eBay ... the quality is superb. He only has an ST-35 board listed now, but keep an eye on this link or email him and ask about the ST-70 board.

http://search.ebay.com/_W0QQsassZtubes4pro

[kheper]

The link for the diy board doesn't work.

If you are referring to my links. They work for me. They are links to full amplifier kits, not just the driver boards.