Let's Restore a Dynaco PAT-5!

What a great job! Thanks for posting this. Great phonos.
I brought my PAT5 back to life after 30 years in my garage. There were several open caps on the main boards. After replacing those it worked, but the phono inputs were too noisy to use. I replaced the power supply with the PAT5PWR kit from Updatemydynaco. The phono boards were a challenge. I looked at kits on eBay that offered all the caps, but that didn't seem like it would make that great a difference. Then I saw another kit on Updatemydynaco. This was a new phono board for the PAT4. I contacted Dan to see if that board would work in the PAT5. He gave it some thought came up with some changes to adapt it to the PAT5's power supply. I installed it and it sounds great. It dead quiet. It's not completely Dynaco but I'm very happy with it.
 
Been very busy lately but I've had some time to spend on the face plate. The original is gold anodized and is missing a bit of lettering. My wife told me no way was that "thing" going in our living room, no matter how good it sounded. I agreed.
I kept an eye out on the auction sites for a silver PAT-5 face but gave up after 2 weeks. I decided I would make the best I could out of what I have.
Here's the original state of the face;
pat-5 face0.jpg
GROSS!

I wet sanded it down with 800 grit to remove the original silk screening and any sharp edges from the stamping process. Then I sprayed it with a metallic nickel enamel. After dry to the touch it was baked at 190 deg. F for an hour.
pat-5 face2.jpg

Next I made my own waterslide decals using AutoCAD software. They are not exactly as the original, and that was on purpose. The original offset and layout just looked "old" to me, though I kept the same spirit as the original printing.
I printed lots of extras in case of any oops moments.
20170222_140619.jpg

Here they are applies with 6 medium coats of clear lacquer, wet sanded with 1500 grit and hand rubbed with Novus #2 compound. It's as smooth as glass. The camera flash makes it look a little more "disco" than it actually is
and all these pics were taken with my crappy cell phone camera.
pat-5 face1.jpg
It's not perfect, but she looks very nice in the console with her big brother. I'm still way under budget on this project so I will be getting some new knobs shortly.
20170226_201223.jpg

I hope you like it. This was a very rewarding project.
Jim
 
Hi Jim, to say that was a nice rehab job would be an understatement. I have a Dynaco Pat-4 pre which was my primary until I got my NAD 1020a. Both are ss, both have phono inputs and both have 2 amp inputs while what the 2nd on the NAD does I haven't a clue. Now, I noticed while trying the balance adjust knob that I think the left channel sounds but not a loud as the right. Together they sound great and normally it's at 12:00 and dos not bother me. I E-Mailed Frank Alstein the Dynaco guru and he said they are to old for him to work on and I should basically drown the controls, knob, pots and most important the female input/output ports. Of course I'm exaggerating on the drowning part but you get what we both mean. Now it's up for sale and I have many pics, could you possibly notice something, anything. Nothing smells or looks fried and all works. I tried to get the writing on the x-former which on the bottom said Dynaco and on top Magnetics.IMG_4147[1].jpg IMG_4151[1].jpg IMG_4151[1].jpg IMG_4156[1].jpg IMG_4157[1].jpg ---something
 
Hi Jim, to say that was a nice rehab job would be an understatement. I have a Dynaco Pat-4 pre which was my primary until I got my NAD 1020a. Both are ss, both have phono inputs and both have 2 amp inputs while what the 2nd on the NAD does I haven't a clue. Now, I noticed while trying the balance adjust knob that I think the left channel sounds but not a loud as the right. Together they sound great and normally it's at 12:00 and dos not bother me. I E-Mailed Frank Alstein the Dynaco guru and he said they are to old for him to work on and I should basically drown the controls, knob, pots and most important the female input/output ports. Of course I'm exaggerating on the drowning part but you get what we both mean. Now it's up for sale and I have many pics, could you possibly notice something, anything. Nothing smells or looks fried and all works. I tried to get the writing on the x-former which on the bottom said Dynaco and on top Magnetics.View attachment 877317 View attachment 877319 View attachment 877319 View attachment 877320 View attachment 877321 ---something

Tom,
It sounds like a gain issue. One channel is either coming out of the preamp weaker, or the amplifier has a weaker output channel. I don't have a PAT-4, but I would download the manual for it if I were you. Usually within the last 10 pages or so Dynaco put voltage test points and values for the boards with recommendations if the point is out of value. I would try that first.
Another thing to check is the volume pot. These Dynaco volume pots were sometimes very out of spec between channels. You can check easily with an OHM meter. Anything more than 5% difference is very noticeable. Notice I put an Alps pot in mine. Mine was off over 20% between channels, and the left channel wouldn't shut off at minimum.
Jim
 
Very nice job on the faceplate! Ill have to do the same with a PAT4 I have. I built a PAS with a reproduction chassis and had a new faceplate made with etched lettering. I did the same with the FM3 I rebuilt. I like what you did though, perfect for the PAT4 also. :thumbsup: 20170125_140052.jpg
 
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Nice face plates! I'm on a tight budget and spent more than I wanted on components internally, but it was certainly worth it. Who made your faces?

Oh, and how do you like the FM-3? I'm considering a FM-5 or AF-6 tuner as my next project, but I haven't committed to anything yet.
 
FM3zone. He will make plates in silver or colors, and what ever holes you want punched along with whatever lettering you want. Just under $100. I like how you did yours. The original plates I had were pretty corroded. I think im going to swnd qnd paint the pat4 like 5ou did, looks nice.
 
This thread has inspired me to rebuild my pat-5

I have a pair of burr brown opa627 integrated op amps I'd like to use. I've never replaced a can type with a DIN type... any tips?

Any one have the replacement transistor part numbers?

I'm also looking at updatemydynaco.com's power supply board kit.
 
Gorgeous work Jim. You are an artisan!

Been very busy lately but I've had some time to spend on the face plate. The original is gold anodized and is missing a bit of lettering. My wife told me no way was that "thing" going in our living room, no matter how good it sounded. I agreed.
I kept an eye out on the auction sites for a silver PAT-5 face but gave up after 2 weeks. I decided I would make the best I could out of what I have.
Here's the original state of the face;
View attachment 877287
GROSS!

I wet sanded it down with 800 grit to remove the original silk screening and any sharp edges from the stamping process. Then I sprayed it with a metallic nickel enamel. After dry to the touch it was baked at 190 deg. F for an hour.
View attachment 877289

Next I made my own waterslide decals using AutoCAD software. They are not exactly as the original, and that was on purpose. The original offset and layout just looked "old" to me, though I kept the same spirit as the original printing.
I printed lots of extras in case of any oops moments.
View attachment 877290

Here they are applies with 6 medium coats of clear lacquer, wet sanded with 1500 grit and hand rubbed with Novus #2 compound. It's as smooth as glass. The camera flash makes it look a little more "disco" than it actually is
and all these pics were taken with my crappy cell phone camera.
View attachment 877291
It's not perfect, but she looks very nice in the console with her big brother. I'm still way under budget on this project so I will be getting some new knobs shortly.
View attachment 877292

I hope you like it. This was a very rewarding project.
Jim
rk
 
Nice work!
I ran across your 400 thread earlier today and read from beginning to end. I just stumbled onto the PAT thread. You do really nice work!:thumbsup:
I'm not looking to do a dynaco build any time soon but i think i'd like to emulate some of the chassis restore work you did on the rusted 400. I'll have to go back and read again.:beerchug:
 
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wow, great shape for $80!
let me know when you're ready. the upgrade is simple and HIGHLY effective.I cant get over how great this thing sounds. others that have heard it are equally impressed, or they're just being super polite.
jim
Thanks Jim! I will definitely see if you can share your parts list with me. I am waiting for the replacement fuses for my multimeter so I can set the Bias on the ST400! Ordered last week and were "delivered" Friday but its the first time I haven't received something from Amazon. They issued a credit today and reshipped. Hope to button up the ST400 soon!
 
Wow! Jim, great work!! I am in the middle of my ST-416 restoration based on your work on the 400 you posted earlier. I have used the PAT-5 power supply replacement and the larger caps and sealed relay from UpdateMyDynaco. I am waiting for parts to replace the 416 power board. The amp is still in progress, but the PAT-5 is in use and already sounds sweet. I will probably use your work as a guide after finishing the 416, but I have a couple of other problems with the PAT-5: The treble bypass switch mutes the sound (not that I would probably use it anyway; it would just be nice to have it fully functional), and the volume control is at loud levels at about 9:00 (through an ST-70 recently rebuilt). This doesn't give me much variation in volume levels. Any ideas? Thanks.
 
What an interesting thread! Thanks
I have a Pat-5 Bifet that is in mint shape, and plan on upgrading as necessary for myself as a keeper.
I have not opened it yet, but wonder if there are any ideas you can put forth due to the Bifet designation?
I have rebuilt a Pat-4 with numerous Updatemydynaco kits, and was more than happy with the outcome, even if I did get a bit over the budget.

Thanks for an enjoyable and educational thread!!
 
Jim,
My rebuild here is to Bifet specs. You can download my parts lists / shopping carts in the link up above. I highly recommend the Dexa op-amps over the original fet style. The slew rate is much better and is much more stable.
They are back in stock at parts connection for $22 each. Well worth it. http://www.partsconnexion.com/product27826.html.
You just have to remove to compensation circuit on the line level boards as the Dexas are self regulating.
See my post on page 1; "C318,C319, and R322 were not installed as the Dexa opamp is internally compensated, meaning Pin 1 on the DIP is not used. Neither are pins 5 and 8."

PS. I FINALLY tracked down a brand new NOS Pat-5 face plate on that auction site. I've been waiting for almost a year to find one. I installed it this past weekend, but now the knobs look terrible. I'm ordering new knobs from Antique Electronics today. I will post pics when I get them on.
Cheers.
Jim
 
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