Best Preamp for use with a Dynaco ST-70

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turkey

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Re: Best Preamp for use with a Dynaco ST-70
« Reply #20 on: 2 Apr 2010, 04:47 pm »
Last question (yes I am a pain in the arse - sry) - what type of gain should I be looking for regarding the preamp selection?

I would think that pretty much any active preamp will work for you in that respect. I believe the "standard" for a line section is 20 dB, which would take a 1V input and amplify to 10V.


turkey

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Re: Best Preamp for use with a Dynaco ST-70
« Reply #21 on: 2 Apr 2010, 05:31 pm »
I have been reading his work - wonderful. I have never tried a diy project yet. I was thinking I should take babysteps in that arena - learning how to solder and electronics 101.

A kit like the ones from Velleman, or the Super PAS 3 kit from AVA require less experience than many of the DIY projects around. These kits give you step-by-step instructions. I would definitely advise that you start with a kit like this. (The Super PAS kit really isn't that hard, but start with something less expensive so you won't have any anxiety about the cost if you fail.)

"Measure twice and cut once" is the key thing to remember.

Give yourself some work room on a table where you won't be disturbed. Lay out the tools you will be using and make sure the soldering iron is close enough to be handy, but not so close you'll burn yourself on it every time you move.

Read through the instructions before starting to put anything together. Using some corrugated cardboard and putting one lead of each component into it so that the components are in the order you will need them makes things easier. (I think Bill Thomas shows how this is done in one of his articles here.)

I normally take a shoebox and put some small dixie cups in it to hold bits and pieces. The shoebox is to hold the cups together on one place, and so that you can put the lid on and put the whole thing away if you have to continue your project on another day. (I don't have a dedicated workbench.)

Don't rush. Take your time. I know it's hard, but try to suppress the urge to be done fast so you can see how it works right away.

"Measure twice and cut once" is a key thing for building electronics.

Do your planning ahead of time, and then when you start building, double-check that you're reading the right step in the instructions and that you read it correctly. Double-check that you're grabbing the right part. Check off a step when you're done with it so you can keep track of where you are.

Make sure you're cutting the right length and color or type of wire before you snip anything. It's really hard to uncut something. :) The same goes for soldering in components or clipping off the leads afterwards.

The soldering itself is the only thing you really want to do quickly. You want to get the solder joint made without heating everything else up too much. On the other hand, you don't want to solder too quickly, or the joint won't have had time to heat up and you'll get cold solder joints. Cold solder joints can often keep the circuit from working. They can also keep it from working at its best, or they can fail later on. So you want to make good solder joints.

Clip-on heat sinks are good to keep from over-heating solid-state components like transistors or diodes. Get at least a couple in different sizes.

I would suggest getting some stranded and some solid core wire at Radio Shack or wherever, plus maybe a few resistors and a terminal strip too. (The ones for point-to-point wiring. They have a number of eyelets attached in a row to a piece of circuit board material.) Try making some solder joints until you get the hang of it. (I'd suggest checking out a tutorial on soldering too, but nothing beats practice.) There are pieces of "generic" circuit board available that have holes drilled in them for component leads. They're used for breadboarding new circuits in some cases. One of these would come in handy to get some practice at soldering on a circuit board. It's a similar process to point-to-point, but I think it's best to see and feel it a few times before working on something you actually want to function when you're done building it.

Now go to it! :)






Leegross

Re: Best Preamp for use with a Dynaco ST-70
« Reply #22 on: 2 Apr 2010, 05:39 pm »
The AVA Insight would be a very good match - I've driven an ST-35 and enjoyed the combo.  (shameless plug)> I have an Insight for sale on this forum.

Another idea is a McCormack RLD-1.  Dual outs and remote but no headphone.  A really nice match with my ST-35.

Lee Gross

nunhgrader

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Re: Best Preamp for use with a Dynaco ST-70
« Reply #23 on: 2 Apr 2010, 06:27 pm »
Thanks turkey for tons of great advice! :thumb:

Leegross - I have been oggling your preamp all week! The lack of remote is no deterrent whatsoever! I'm stuck between two purchases  (the amp and a set of Tektons) so cash strapped :(. I should be out the forest in a week or two but, your preamp will be long gone by then - I've watched Mr. Alstine's products sell very quickly!


My timing has been crappy but, I kind of lucked out on the passive preamp bid not being selected.
« Last Edit: 2 Apr 2010, 07:44 pm by nunhgrader »

turkey

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Re: Best Preamp for use with a Dynaco ST-70
« Reply #24 on: 2 Apr 2010, 07:12 pm »
Thanks turkey for tons of great advice! :thumb:

Leegross - I have been oggling your preamp all week! The lack of remote is no deterrent whatsoever! I'm stuck between two purchases  (the amp and a set of Tektons) so cash strapped :(. I should be out the forrest in a week or two but, your preamp will be long gone by then - I've watched Mr. Alstine's products sell very quickly!


My timing has been crappy but, I kind of lucked out on the passive preamp bid not being selected.

Maybe Lee would let you put a deposit on it or something? If that's the preamp you want, see what you can work out. It can't hurt to ask. :)


baldrick

Re: Best Preamp for use with a Dynaco ST-70
« Reply #25 on: 5 Apr 2010, 02:24 am »
Here's a suggestion.  I'd eagerly buy this preamp if I were in the market for one:

Mapletree Audio Ultra 4M review

Link to Mapletree Audio

Handmade, quirky and good sound.  Got to love it.
Best of all, Mapletree makes a kickass driver section for the Stereo 70.  All point to point, and a super clean look to boot.
Check it out here:
Mapletree St70 driver

Happy hunting

hapinoregon

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Re: Best Preamp for use with a Dynaco ST-70
« Reply #26 on: 28 Apr 2010, 08:09 pm »
I use a Creek OBH-12 passive with my Will Vincent modified ST-70 driving 1971 Klipsch Heresys.

Excellent clean, open, warm sound with a dynamic range than can peel paint of the walls.

Highly recommended...