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W/O FURTHER ADIEU MS-475 - "Cousin of Frank"
Posted: Sun Jan 11, 2009 10:16 pm
by mhyde71
started with today removing the boards from the 275 sinks, and replacing the cap's.
Everything went well for the first board/half, now onto the second.
QUESTION(s):
1) I tried cleaning the board up with laquer thinner and paint remover. Nothing bad happened just cant get the crud/junk off the board's nice gold plate??? any other suggestions???
2) i have the nice blue/silver twisted wire, what do you like to see in there the red/black or blue/silver??? I kinda like the different wire (blue/silver) wire better?? 2a) Doesnt matter so much to me, but if I do that, should i also then change the LED's to maybe blue or something?? Keeping in mind that, in the end/final product, it will have the franked trim work and color of text on the persplex... a purple-ish/pink-ish trim (aka franked). The plexi will also be pinkish/purple-ish too with PG Logo on there as seen on the end caps now.. with the Franked "Phoenix Gold".
3) What do folks suggest filling the holes in on the heat sink?? and is it even neccessary? I am thinking that it might prohibate/restrict disapation with various voids in the sink. So I thought of filling them up... JB weld type of stuff, or two part expoxy weld mix? or just drop some solder in there?? plan is that whatever I drop in there and once sanded and smoothed out, go have it anodized. 3a) Or do the holes not even need to be filled/plugged up???
4) Should I throw in Burr Brown's?? does it matter/make a difference?? If so, I'll do it!
Posted: Mon Jan 12, 2009 12:24 am
by mhyde71
Just to get/give a sneak peak of the two boards laying along side each other in the sink....
I like the mirror image the two amps make sitting back to back with each other.. the speaker wiring and caps and stuff... looks cool reversed like that... might look good with PG surfer logo instead given that kinda swirly thing going on. hmmm...?
You can also tell which board has yet to be cleaned and re capped pretty easily enough...
Excited to get'er completed and all polished off, like it so far..
Still have same concerns/need for suggestion(s)...
See first post...
Posted: Mon Jan 12, 2009 7:23 am
by Rold Gold
Looks pretty good Matt........ I see that sink is being put to good use.....
Posted: Mon Jan 12, 2009 8:28 am
by rolandk
Cool! Try using a pencil eraser to clean the circuit boards.
franked
Posted: Mon Jan 12, 2009 8:28 am
by kg1961
very nice!!!!

Posted: Mon Jan 12, 2009 8:35 am
by mhyde71
rolandk wrote:Cool! Try using a pencil eraser to clean the circuit boards.
nice, will do/give it a shot! Thank you!
and as an update:
1) Decided to go with Burr-Browns- They're ordered and on their way.
2) think i am going to fill holes with devcon metal hole filler, sand, and have anodized black, gold or violet.
QUESTION TO ROLAND (or anyone actually that might know): Are the heat sinks (2250's originals) have they been anodized on the inside? I ask, b/c I dont think you can anodize on top of something that has been anodized... or if anyone else knows?? looks like it has, but could just be the finish...?
Posted: Mon Jan 12, 2009 8:11 pm
by mhyde71
any other input??
Posted: Mon Jan 12, 2009 10:40 pm
by marko
think the sinks are anodised all over, don't think you could anodize just that area anyway? i'm sure they anodized them so they didn't have to use sil-pads?
Posted: Thu Jan 15, 2009 6:27 am
by mhyde71
marko wrote:think the sinks are anodised all over, don't think you could anodize just that area anyway? i'm sure they anodized them so they didn't have to use sil-pads?
Anodized on the exterior and Possibly anodized on the inside? I have an email into Matt J, we'll see i guess... Or i could just bring to shop that does the anodizing for us and see what he says.... but i do know you can not anodize over anodize.
Posted: Thu Jan 15, 2009 6:30 am
by thedeal7235
Matt, can you be more specific, on what componenets of the amp, gotburr-brown upgrade? thanks-Christian( i know burr brown (in a h/u is d/a conversion, not sure what it does on a amp?
Posted: Thu Jan 15, 2009 6:43 am
by mhyde71
thedeal7235 wrote:Matt, can you be more specific, on what componenets of the amp, gotburr-brown upgrade? thanks-Christian( i know burr brown (in a h/u is d/a conversion, not sure what it does on a amp?
there are 3 OPAMP spots/on the amps that can get the BB's...if I'm not mistaken they are outputs / output based/affliated... IOW versus inputs/input circuit... but maybe 1 of them is dedicated for input circuitry, but I dunno the specifics.. I just know where they go. (see pic's)
I have never done an A versus B comparison... I have heard that they make little to no difference, but from others I heard they swear by them. So I wanna try'em out.
Might add a little value to the project, or might actually decrease value, as it is not OEM...but then-again, neither is the whole amp/project anyways, so what the hell ya know??? I thought it would be good time to check'em out.
But i havent done them yet, they will probably be here shortly, and after reading your post once again i think maybe you were asking where were the BB's in the amps pictured in the franked 475?? you wont see them there as I havent done them yet...m
Posted: Thu Jan 15, 2009 6:44 am
by thedeal7235
excellent(nice job, btw, and if u hear a difference let me know-btw, how much were those (ics) I believe they aare called?
Posted: Thu Jan 15, 2009 7:06 am
by mhyde71
thedeal7235 wrote:excellent(nice job, btw, and if u hear a difference let me know-btw, how much were those (ics) I believe they aare called?
you mean the bb's opamps? i haveen't ever heard them call ics's.. but could be wrong.. anywho-
Got package of 10 for 50.00. if you're referring to the op amps.
Posted: Thu Jan 15, 2009 7:15 am
by joerg
mhyde71 wrote:thedeal7235 wrote:excellent(nice job, btw, and if u hear a difference let me know-btw, how much were those (ics) I believe they aare called?
you mean the bb's opamps? i haveen't ever heard them call ics's.. but could be wrong.. anywho-
Got package of 10 for 50.00. if you're referring to the op amps.
IC ist short for integrated circuit! I used to learn it to name it that way in school.
Posted: Thu Jan 15, 2009 8:20 am
by stipud
Be careful soldering in those ICs... too much heat from the soldering iron, and you'll kill them. Personally I always install IC sockets, and then clip them down. I wonder if they have any sockets that would fit your amp? Then you could switch them back and forth easily as well.
Posted: Thu Jan 15, 2009 8:23 am
by marko
sinks are anodised and end plates painted or powder coated, i know as i have 2 stashed away! this is only on the original ms2250 with shroud.
Posted: Thu Jan 15, 2009 10:19 am
by rolandk
mhyde71 wrote:
QUESTION TO ROLAND (or anyone actually that might know): Are the heat sinks (2250's originals) have they been anodized on the inside? I ask, b/c I dont think you can anodize on top of something that has been anodized... or if anyone else knows?? looks like it has, but could just be the finish...?
Sorry for the delay in replying but I had to discuss with a few people first.
The heatsink is anodized but we highly recommend using either the standard MS275 sil pads or the black aluminum anodized insulator strips and bar clamps used on the later MS275's.
If you use sil pads be very careful securing the big transistors (output XSTR's and PS FET's) to the heatsink. It is critical that the entire backside of the transistor is flat against the heatsink. If there is any air gap the transistor will overheat and fail in just a few minutes. What I suggest doing is:
1. Mount the PCB's in the heatsink.
2. Mark the transistor mounting holes in the heatsink.
3. Remove the PCB's and drill the holes.
4. Desolder and remove all of the big transistors. Be careful because its easy to damage the pads and traces.
5. Install PCB's in the heatsink again.
6. Install transistors and sil pads. Screw the transistors to the heatsink and make sure they are flat against the heatsink BEFORE soldering. Also use compression washers.
7. Solder the transistors.
Good luck!
Posted: Thu Jan 15, 2009 10:19 am
by thedeal7235
Sorry Matt, Im really bad at reading( im a visual person), but i noticed your 1 question about cleaning crud off the board, and if some 1 else already said, my bad for not reading thouroughly, but sometime ive found that a very fine toothbrush(never used with toothpaste-like new)with some rubbing alchol, and gentle agitation with the two, takes that crud away-just my experiences and my suggestions-
Posted: Thu Jan 15, 2009 11:04 am
by mhyde71
rolandk wrote:mhyde71 wrote:
QUESTION TO ROLAND (or anyone actually that might know): Are the heat sinks (2250's originals) have they been anodized on the inside? I ask, b/c I dont think you can anodize on top of something that has been anodized... or if anyone else knows?? looks like it has, but could just be the finish...?
Sorry for the delay in replying but I had to discuss with a few people first.
The heatsink is anodized but we highly recommend using either the standard MS275 sil pads or the black aluminum anodized insulator strips and bar clamps used on the later MS275's.
If you use sil pads be very careful securing the big transistors (output XSTR's and PS FET's) to the heatsink. It is critical that the entire backside of the transistor is flat against the heatsink. If there is any air gap the transistor will overheat and fail in just a few minutes. What I suggest doing is:
1. Mount the PCB's in the heatsink.
2. Mark the transistor mounting holes in the heatsink.
3. Remove the PCB's and drill the holes.
4. Desolder and remove all of the big transistors. Be careful because its easy to damage the pads and traces.
5. Install PCB's in the heatsink again.
6. Install transistors and sil pads. Screw the transistors to the heatsink and make sure they are flat against the heatsink BEFORE soldering. Also use compression washers.
7. Solder the transistors.
Good luck!
Okay, Very Good and Thank you Roland... !
Any/all input is greatly welcomed & appreciated!
It's actually funny that you suggested the black aluminum anodized insulator strips and bar clamps - I just sent email to Matt J. asking about securing a few of those for me.... Perhaps you could point him in right direction now that you are somewhat intimate with what it is I am looking to do... i.e. what exactly I would need/require to do it with respect to the insulator strips and bar clamps, as that is my preferred way to go...??
Pls & Thx, Many Many !
Posted: Thu Jan 15, 2009 11:37 am
by rolandk
Yeah Matt asked me about that. I just looked at our stash of insulators and hold down bars and didn't find anything for the MS275 or 2250. Sorry

Posted: Thu Jan 15, 2009 12:20 pm
by mhyde71
oh, okay... well that's cool, thank you for looking into it for me...!
perhaps someone on here then might know (or even you Roland) as to maybe athrid party (i.e. digi key, mouser, etc... )That may have something just like it, or at least simliar in function/looks...
If not, it's not the end of the world, I can simply use the sil-pads I guess...
Is it okay to use sil-pads on the anodized aluminum??? I suspect so as it was suggested by you (Roland), but just wanna confirm...?
pls thx
matt
Posted: Thu Jan 15, 2009 12:28 pm
by rolandk
Not sure if anodized insulators are commonly available. If you end up using sil pads they are fine with the anodized heatsink.
Posted: Thu Jan 15, 2009 12:31 pm
by mhyde71
rolandk wrote:Not sure if anodized insulators are commonly available. If you end up using sil pads they are fine with the anodized heatsink.
Okay cool, and thanks again! I appreciate it!
OH AND HEY! I really dig your Avatar... it is like so fitting (not sure that is really the best word for what I wanna/try to say) but i get it, love it, etc..., more than some may think... funny!
Posted: Thu Jan 15, 2009 3:08 pm
by Pedi
mhyde71 wrote:OH AND HEY! I really dig your Avatar...
Not as much as you LOVE mine, hehe...
j/k...
I just wanted you to see a pic of what you should get from PG... It is strange that they had in stock one year ago, and none left now... Is it not possible to get them from anywhere else???
Posted: Sun Jan 18, 2009 12:15 am
by mhyde71
rolandk wrote:Yeah Matt asked me about that. I just looked at our stash of insulators and hold down bars and didn't find anything for the MS275 or 2250. Sorry

might there be a comparable type piece in stash of insulators and hold down bars , I'd be inclined to go with maybe something from/for a TA (if they were on the TA's)...
But I bet those are probably some of the most used for repair pieces...up there with caps. Typically when damage occurs within that area I would think and affects that area pretty good.
pedi wrote:Not as much as you LOVE mine, hehe...
Nope yup, ahhh... much more in a whole different way though
Any extras over that side of the pond Pedi??
sorry about not responding sooner.. I dont/didn't recall getting/seeing email for response, oooops !