| Author | Message | ||
| greg |
i've taken stock of the caps in my amp, here is the list i came up with- 2- 100MFD 450VDC 2- 400MFD 25v 2- 150MFD 50v 5- 20MFD 25v 1 150MFD 3v 3- marked sprague 300 TE1201 2-25dc do i or should i replace all of them, or do i only need to do some of them? | ||
| mike kaus |
The ones that you need to change are the electrolytic caps which are metallic and round(don't think I ever saw any square ones!) Don't have a schematic for a 150 here but the main circuit board has a few and so does the normal rectifier board and filter board. Sound like you have them. Rememeber, only the electrolytics need changing unless they are bad. Replace them all. | ||
| greg |
thanks for the response, mike. those are all the electrolytics i could find. the 100MFD 450VDC cap, can i use a sprague that doesn't specify "DC", or do i need to get that one specifically made for DC. also, what the hell is that last cap on my list (sprague 300...)? is there a substitute? i've searched a couple of the sites posted on another thread and haven't found either of these. | ||
| mike kaus |
Look at the mouser catalog-here's the link to there vishay page which is sprague. http://www.mouser.com/catalog/624/540.pd f This should take you right to it. It's on the right side. Mike | ||
| greg |
thanks again mike, between mouser and antique i was able to find all of them except the 2-25 sprague's. they're in the tone circuit, and i wanted to check back to see if you knew of a suitable replacement that wouldn't mess with the sound(the guy at mouser thought it might) greg any experience with this, or am i better off just leaving them in? | ||
| mike kaus |
The page I linked to list's the TE1301 which is the 2mF@50V. It's probably a part number thing that they made the 25v cap for a short time and just stopped making it. Use the TE1301 -it's just a 50v cap instead of 25. It will be fine. | ||
| greg |
hey mike, once again, i appreciate you taking the time to answer my questions. it appears, and i'm guilty of it as well, that the same questions are repeated here, and i can only assume it gets somewhat frustrating. but you have made my life (and amp project)infinitely easier. muchos gracias! all parts are in the mail. | ||
| mike kaus |
Just wanted to know if you got your amp recapped ok. Sometimes they can be a bas$%rd if you actually lift the cicuit boards up to go underneath. I usually rodeo tie the ends above board and then solder. After 25 years, none have come lose yet. If the board is easy to get up, I do that. The ones on the main circuit board with the preamp stuff get tied and soldered. Not real familiar with te 150's so I don't know what the board situation is like. Mike. | ||
| greg |
yes, everything went according to plan, and i've been using the amp at my last three of four shows. the amp sounds incredible and is very quiet, except when i turn up the reverb...which i don't use anyway. a vast improvement over the way it was. i have pics i want to post but haven't downloaded them offf my camera yet. it looked as though the amp had a lot of use, and i took some pics of an area that i suspect may have been modified...maybe interesting to you at least. at least one of the resistors on the tube sockets was open, and the others were nowhere near their stated value. is it possible to use the reverb send to send a signal to a power amp? does the reverb send get it's signal before or after the tone circuit? thanks again for all your help, it was invaluable. long live music man amps! | ||
| mike kaus |
The reverb send looks like it come after the tone, in fact it's keyed off of the master send through a 56k resistor into IC4. I would think that would be a pretty hot signal but I could be wrong. It looks like it dumps directly into an IC as a buffer at IC8 so maybe it COULD be used. I don't see an effects send or return on that amp. I thought they had one. That would be the place to do it if it had one. | ||
| edward solberg |
Hi Mike, didn't mean to make it seem as if I was blowing you off after mining your knowledge back in november; work took me to a very remote location and I just got back in country in mid-january... long trip. I had the laptop with me but couldn't access the musicman site until getting back to my desk machine--damned laptop just didn't have the nads to upload the main page. anyway, to cases. I agree with greg that you (among a select group of "others") are a real asset to this forum. you seem to tirelessly answer the same questions over and over--without a trace of smugness or seeming bored from covering the same old ground with every FNG (present company included) wanting to get his hands dirty in the gutz of his music machine for the first time. I add my thanks for all of your help back in october or november. being an old hand electrician (big wires, lots of volts and HIGH ampacities), I couldn't help but smile at your admission of "rodeo-tying" and soldering component leads hidden beneath an impossible-to-access PCB. some may sneer but, by the time one reaches the back side of hisfifties, we have a much more accurate appreciation of just how valuable a commodity our time has become. your candor was refreshing--to say the least. thanks again, ed | ||
| mike kaus |
I appreciate the comments. I've gotten to the point that the guru opinions don't really sink in to me anymore. My choice of tying and soldering above board has been tested for many years before I shot my mouth off. I consider this a quality fix and have been doing elctronics (high and low voltage) for about 30 yrs now so I don't do things without a certain amount of practical knowledge. Removing a circuit board that has been in one spot for 30 yrs is inviting disaster with a PC board. that crap get brittle and traces lift and all sorts of bad mojo is lurking. Be smart, be practical ,and be safe. I always figured if they could make twist connections work for years, good quality solder joints should last for decades. Ramble over. Mike. | ||
| Martin Lopatosky (marty_l) Username: marty_l Registered: 06-2006 |
I have a 212HD 150 combo amp, it's time for a cap job. One of the 100mfd 450v caps has a small bubble on it. My cap list is the same as Greg's. I found all but the 400mfd 25v caps at mouser. Does anyone know where I can find these? Thanks and God Bless!!! Marty L. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
If they have them in the higher voltage rating, go ahead and get them.. The only thing important is the voltage rating and if they have a 450 or 500mF at that voltage rating OR highr, that will work also. Don't have a 150 here-where do thay use that? Cant be in the bias circuit. Got to be in tone somewhere. | ||
| Martin Lopatosky (marty_l) Username: marty_l Registered: 06-2006 |
I'm not a tech and don't yet understand how the current flows through all the components, on the schematic the caps(numbered C60 + C62) are in the area of the power feeds on one side(orange feed from trans) and +16v and -16v points on the other side. Thanks for your help Mike! God Bless!!! Marty | ||
| Terry Loose (terry) Username: terry Registered: 05-2006 |
Hi Martin I have them if you want two Email me Terry. |
Tue, 03/25/2014 - 09:27
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