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johnnyjcap1 year ago
I just joined this site to see if you are still available for info regarding the stereo tube amp? I wrote a nice detailed paragraph stating my situation but for some reason it was deleted and I lost it. Please respond if you are still available for correspondence.
thobson (author)  johnnyjcap1 year ago
I'm here!
Hello! Sorry it took so long to get back to you. My PC & internet is both giving me grief. I am glad to see you're still out there.
I've been doing SO much research on this topic & right now cost is my main issue. I am considering either trying to build your amp, or buy a DYNACO ST 70 on Epay & rebuild it myself. The reason I chose the Dynaco is that there is so much info out there on rebuilding, what with forums & such.
Ether way I'll still need a Pre-amp, since I'll be using multiple inputs. IE: Tuner-(maybe). CD, Phono, and a possible DVD Audio out/in. What do you think of my situation?
I don't remember if I stated before, but I'm disabled & on a fixed income. I have been saving, but Christmas is coming & my Grandson is in the picture (he's 4) I will be getting a settlement check in Jan/Feb. that will pay for MY toys. So any input you can provide me will be VERY appreciated!
My son also knows how to read electrical schematics & said he'd help me as well.
thobson (author)  johnnyjcap1 year ago

Well, you're definitely right that there's more info out there on the Dynaco. However, that's not to say that there isn't enough on the amp in this instructable. The instructable and poindexter's documentation ( provide plenty.

If you want to use a turntable, you'll likely need a preamp, although some turntables have them built-in, I think. I can't speak to what you might need with a DVD player or radio, since those devices vary so much. They may have amplifiers in them, they may not. You would have to check the specific device you intend to use. I do know that this amp can definitely be driven by a computer's sound card and an MP3 player, which are what I tend to use.

Hi, I figured that if the component doesn't have is own output volume/tone controls/balance.
It needs a preamp in order to boost the signal to a proper amplifier level, or to at least provide a volume control. A CD Player/ DVD Player (at least mine) doesn't have this. As well as my Phono Player & Tuner. The Tuner I don't use very much as I can only pick up the local Collage Radio station (bogus) and some very distant Richmond stations. The Phono is what started all of this, as I have an extensive vinyl collection from my youth, 225 -250 in impeccable condition, that I would like to visit again!
So this would be my main focus for now.
I'm looking at these Chinese Preamps, link:
I've read alot of good things regarding these preamps, and with a few mods they supposedly are really spectacular. I don't know how many mods I will be doing at first, but once I'm into this & the bug has bitten me pretty good, who knows!?
I hate bothering you everyday, but if you've got some time the next few days, could you take a look at the link to the preamp and let me know what you think?
Thanks for all your time. Johnny.
ajande3602 years ago
I had some questions about the tube amp schematics.

Do you use one 5965 tube and two 6v6 tubes per channel?

The power supply looks like it one 5965 tube and one 6v6 tube, is this the case? do you just pick one of the tubes to use?

Where exactly is the output on the schematics?

I would appreciate if you would be able to help out with these questions.
thobson (author)  ajande3602 years ago
-------Do you use one 5965 tube and two 6v6 tubes per channel? -------

Yes. The 5965 is a dual triode, meaning it is a single tube containing two triodes.

-----The power supply looks like it one 5965 tube and one 6v6 tube, is this the case? do you just pick one of the tubes to use?---------

The power supply needs to be connected to all of the tubes. What looks like a single 5965 represents all of the 5965 tubes in the amp, meaning that pins 4, 9, and 5 of every 5965 need to be connected as shown in the schematic. Same goes for the 6V6 tubes.

-------Where exactly is the output on the schematics?-----

The output is in the audio circuit schematic, coming off of the 125D output transformer.

Thanks for your help. I just have one more question about the circuit.

Unless otherwise noted in the schematics, are all resistors 1/2w?
myc20044 years ago
 How much experience do you have with electronics?  How much time do you think you spent on building this?  Also what inspired you to create the stereo tube amp?  
thobson (author)  myc20044 years ago

You don't necessarily need to have a wealth of experience with electronics in order to put this amp together; as long as you can follow a schematic you can build it. The reason I wouldn't recommend this project to someone inexperienced electrically is the safety issue. The amp runs at a high voltage and has a lot of current going through it, so the risk of shock is quite high in comparison to many lower power electronic projects.

I would say it took a weekend or two to assemble the amp, once all the parts had arrived.

There are a lot of reasons for wanting to make a tube amp. First of all, they're just cool. They glow, they're glass - they have a high retro appeal. Secondly, they do sound great. Mostly though, it's a great educational experience. Modern electronics don't really use tubes like they used to (with the exception of boutique audio equipment and guitar amps) so building a tube amp is a good opportunity to learn about an old technology as well as give you some perspective on the development and history of electronics.

lenhan17085 years ago
Dear Thobson how much does it cost, when its finished? Thanks
thobson (author)  lenhan17085 years ago
Hi, I didn't keep track of the cost very well while I was building it, but I would say that it was somewhere in the area of $150-$300. thanks for your interest!

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