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Re: Might have made an oops

June 23rd, 2016, 3:21 pm

70$ is very reasonable. Building a case is not a problem. Is there a good resource for plans etc ? I see what has lots of kits but thought those were not good options due to quality

Re: Might have made an oops

June 23rd, 2016, 4:09 pm

There is not really much to the gain stage. Basically the OP Amp, a feed back resistor two input resistors, an output resistor for stability and small bypass caps close to the input + and - supply leads of the amp. Then whatever switching you need for the inputs you want and a stereo pot. The power supply can be as sophisticated as you want. I have some ideas there that have worked for me. If you let me know what inputs you want I can draw up a schematic with values for you. I also have lots of parts like the bypass caps since I buy them in bulk which you can have for free.

Probably the easiest way to build the board is to use Vector perfboard with 0.1 inch spacing holes. I also usually put the power transformer, rectifiers, and first stage filtration is a separate small box to keep it separate from the signal circuitry. The best hum reduction comes from distance.

Tom

Re: Might have made an oops

June 23rd, 2016, 4:45 pm

And you've quickly blown way past my zero knowledge level of electronics. If I truly don't understand what you said, I'm guessing that means this is not something I should try to do ? Or is it the perfect way to learn ?

Re: Might have made an oops

June 23rd, 2016, 5:21 pm

Tom threw you into the deep water without a life preserver. :shock:

Without the background to do it yourself -- hiring someone, even a DIY guy with time on his hands, will cost as much as a used inexpensive pre-amp that you can buy on eBay.

My two cents and I expect change.

Re: Might have made an oops

June 23rd, 2016, 5:21 pm

I live in North Potomac. If it is convenient for you to come over we can build the board here. It will not take much time and it would be a good way for you to learn. I should have all the parts you need for the board except for the transformer. I can dig up something that would work short term until you can get a permanent one.

Tom

Re: Might have made an oops

June 23rd, 2016, 5:27 pm

Speaking of a DIY guy with time on his hands. :lol:

Tom's offer is very generous and he has many DIY scratch-build projects under his belt. You could learn a lot in a very short time.

Especially soldering small devices. You can easily "heat-fry" an op-amp if not careful.

Re: Might have made an oops

June 23rd, 2016, 5:30 pm

SoundMods wrote:Speaking of a DIY guy with time on his hands. :lol:

Tom's offer is very generous and he has many DIY scratch-build projects under his belt. You could learn a lot in a very short time.

Especially soldering small devices. You can easily "heat-fry" an op-amp if not careful.


The advantage of being a retired old fart.

Tom

Re: Might have made an oops

June 23rd, 2016, 5:46 pm

JDCrae wrote:And you've quickly blown way past my zero knowledge level of electronics. If I truly don't understand what you said, I'm guessing that means this is not something I should try to do ? Or is it there order way to learn ?


How much of a time crunch are you in for this one?

It's probably above your budget, but I throw it out anyway.

I have a real and unmodified (can you believe I own anything unmodified!!!) Dynaco PAS3X. Yes, it is the "X" version as verified by the control rotation. This means that when the knobs are centered, the tone controls are out of the circuit.

I have never used this, bought at a flea market. Plan was to clean it up and sell on eBay for the $250-$300 people seem to pay for them.

If you can wait until after the show, I can still get it working (you can help and learn!) and you can have it for $150. It will be working or no obligation on your part.

This is a tube preamp with a reputation for good sound. It has a moving magnet/ceramic phono section. WAY better sound exists, but I bet this suits your needs.

But I have SOOO much to do, this has to wait at least a month.

OR, I have two old Lafayette solid state receivers, both in need of TLC, (mostly for the power amp sections), either or both of which you can HAVE free! Just pick them up!

If I keep the Lafayettes, they will get LM3886 chip amps, sound way better, and be used in the garage.

The LR1000TA was the first receiver I ever bought at about 14-15 years old. I saved paper route money for a couple of years to buy it. It sat around for decades after I moved on to tubes and better SS. Later, it lived in a barn on a dude ranch on the Eastern Shore for around four years, until the owner died. It played cowboy music for the horses, but got quite dirty and beaten up. When the owner died, it was going to be thrown in the trash, so I reclaimed it. Supposed to donate it to a charity, so I can take a little tax deduction, then, of course, the charity will toss it. An inglorious end to a piece of my life.

The LR1500TA was bought from a thrift shop. It was the receiver I wanted, but couldn't afford.

Happy to help, but really short on time right now.

Stuart
Attachments
1500TA_inside.jpg
LR1500TA.jpg
1000TA.jpg

Re: Might have made an oops

June 23rd, 2016, 6:18 pm

rear of 1500TA

I don't have any picture of the PAS3X, only a side view in a pile of gear. Sorry.

Stuart
Attachments
Equipment.JPG
1500TA rear.jpg

Re: Might have made an oops

June 23rd, 2016, 7:15 pm

Tom,

I cannot thank you enough for your offer to help. It is very gracious of you. I would absolutely love to take you up on that offer, if only so I can understand what goes on in those black boxes. I have never been to N Potomac, but its hard to imagine its too far to go. What is your schedule normally like ? I work all week, but weekends are typically pretty open. Just let me know what can work for you. As far as the transformer goes, if you let me know what to look for, I would be happy to source that beforehand so we have it. Inputs wise, I would like one input for an rca to mini jack, so I can plug in my phone, and an input for the turntable. I know nothing of turntables, but the one in the console works, or I should say it did. It used a pair of rca's, but also had wires going to what I believe was a tranformer. It was very small, maybe 2 inches cubed. Have never had one that wasn't encased so I can't help much more than that.

Stuart,

I really appreciate your offers as well. I wish I could say I understood more about the ones you mentioned, but my knowledge is just too limited. I have some time, as I can use the Niles as is, its just I have to control the volume using my phone. It does have separate line level controls which is nice, as it allowed me to perfectly match the outputs by ear anyway. Pretty handy feature. Down the road if you still have some gear you wouldn't mind parting with, and I know what I am looking at, I may take you up on purchasing one from you.


Jeff
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