ISO Schematics for a Baldwin D1 Guitar Amplifier For Trouble Shooting A Friends Amp Has Low/Distorted Almost no Volume On One Channel And The Other Has No Sound The Reverbtank Seems To Have Clean Sound Going To it Can Hear Tank Good When Tapped On
Teemuk kindly redrew and posted here the Baldwin C1 schematic, should be close enough to troubleshoot or give you helpful tips.
http://www.ssguitar.com/index.php?topic=592.0
Sorry for the thread necro, but I have the same issue on mine. Were you able to fix it? If so, how?
Hi NOD, please post what happened to yours, in detail.
It's very unlikely that 2 amps have the exact same problem and need the exact same solution.
Doesn't sound or sounds weak or distorts can have a gazilliuon differet causes, in any and all cases you need to troubleshoot your own.
Thanks for the reply, JM! With mine, ch1 (rev, trem) is non existent. THe previous owner stated it got quieter then barely there, but fizzy. Pretty much like the OP said. The CH2 is fine (and sounds excellent!). I just picked up this amp today, so I have no history with it.
The first thing I am planning to do is replace all of the electrolytics. Seems like a good idea on a 45yo amp. I was just wondering if there were any other areas to look for in particular.
While I am asking, whta type of cap is the Sprague 157p? I have a ton of them in this amp of various values and am thinking they do not age like electrolytics. For example: https://reverb.com/item/1202205-sprague-056uf-157p-capacitor-1965-tan
Hi, may I suggest that the first thing to do is NOT replace a lot of caps, but to fix the problems the amp has first. Once it works, THEN go back and upgrade any parts you feel the need to. BY wholesale parts changing, you not only greatly increase the possibility of ADDING problems, because we ALL make mistakes. Also, changing the caps may change the symptom or otherwise potentially mask the original problem and make it harder to find.
The caps are metalized paper or film, I'm not sure which. I have some old Sprague catalogs, but not here. They don't age the same as lytics, but they do age. Some last forever, some don't. I test them by function. If they are leaking C in circuit, then they are leaky. If they don't then they are likely OK. If one or two are leaky, then there is a good chance they all are. The old wax covered paper caps are almost always leaky. (A heat gun melts off the wax so the print is easier to read) I used to rebuild old jukebox amps, and those almost always needs a boatload of caps.
Quote from: Enzo on November 20, 2015, 02:16:54 AM
Hi, may I suggest that the first thing to do is NOT replace a lot of caps, but to fix the problems the amp has first. Once it works, THEN go back and upgrade any parts you feel the need to. BY wholesale parts changing, you not only greatly increase the possibility of ADDING problems, because we ALL make mistakes. Also, changing the caps may change the symptom or otherwise potentially mask the original problem and make it harder to find.
The caps are metalized paper or film, I'm not sure which. I have some old Sprague catalogs, but not here. They don't age the same as lytics, but they do age. Some last forever, some don't. I test them by function. If they are leaking C in circuit, then they are leaky. If they don't then they are likely OK. If one or two are leaky, then there is a good chance they all are. The old wax covered paper caps are almost always leaky. (A heat gun melts off the wax so the print is easier to read) I used to rebuild old jukebox amps, and those almost always needs a boatload of caps.
Enzo,
Thank you for the guidance! I audio probed the amp until I found the break in the circuit. It was at the cap leading into the volume pot. I replaced it, but the volume is still very low.
I just re-read the Teemuk thread and am going to look over the revised schematic that I didnt see previously. I'm glad he posted that because there either was some serious drift in the preamp (R1, R2 and R3) or my meter was way off....but then that was the Baldwin revisions and everything was close to spec now.
Without having as scope, I am not sure where to go from here. My tech is months backlogged, so I am wanting to do it myself if I can. I studied EET in college in the 90s, so I know a little bit, but my meager skills are fairly rusty. So I am looking to enjoy the process a little bit, but will definitely call uncle if I get overwhelmed.
Any help would be most appreciated! Thanks in advance to all of you smart guys and gals out there.
Pics or if didn't happen, right?
(http://images.tapatalk-cdn.com/15/11/22/8a920ad0a0e953e9c7043e14d37ca66a.jpg)(http://images.tapatalk-cdn.com/15/11/22/c4075d6f9a81b5dcba6dacb778b86208.jpg)(http://images.tapatalk-cdn.com/15/11/22/23be2e558c6fae1dd95253e2e4351c76.jpg)(http://images.tapatalk-cdn.com/15/11/22/9ea81be60d4110c3aa04879a02561bf7.jpg)
(http://images.tapatalk-cdn.com/15/11/22/1b7a86608974c524ef6fbf0585f9af88.jpg)
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You are chasing down a substantial loss of signal level, not some subtle distortion or noise, so a signal tracer is as good as a scope for this.
I missed a link to the schematic you are using, the teemu schematic does not have part numbers.
Just because you found a bad cap at the volume control doesn't mean there are not more of them. You may well have to change a lot of caps, I just warn against doing it up front. if you got signal up to that cap, do you now have signal on the control? If so, continue down the signal path. Does it go further from there?
Thats encouraging, thank you for the help! I'll report my findings as I trace the signal path to the power amp. Hopefully something will be obvious. But you're saying that it may be: find an issue, fix it, keep tracing, find another issue, rinse and repeat?
Since this is a less common amp, resources are kinda scarce. I have Teemuk's schematic, and another one I found on my own searches. It appears to be a scan of the real thing, but the text is really hard to discern. Let me know if this helps shed light.
Do we know if the schematics on http://www.musicparts.com/products.asp?Company=Baldwin are worth the $20? Or is it the same incomplete version I keep hearing about from the Jack Darr book?
not one to give in so easily, but I've got too many irons on the fire so I dropped it off today at the tech.
I have a tube amp that I wat to sell that could use some love in the meantime...
Does anyone have a Baldwin D1 amp for sale?
Thanks.
I may sell mine. It's getting refurbed right now at the shop
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What's the condition? Do you have any photos? How much do you want?
Thank you,
Robert
Robert, I'm not sure how much to sell it for until I get the bill back from the shop. I should see it first part of next week and then I'll make a decision whether it stays or not. The pictures of the amp are in this post above. Where are you located?
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I'm in New Jersey. I have 2 of the 2-12 versions of the amp (Baldwin C1). I am going to sell them because I have a herniated disc in my back and they are too heavy.
Let me know if you want to sell it when you get it back. Also, I do have a couple of C-1s if a trade is possible. Either way is fine.
Thanks,
Robert
Robert, it turns out that the tech lost the work order And wasn't able to reach me. It's been done for more than a few weeks :). Anyhow, I got it back yesterday and I completely understand why you would want to have one of these amps around. It has probably the best tremolo I've ever heard in my life. I am tracking guitars for an album for the next couple of weeks or so. I will get back to you afterward whether it stays or goes. I'm likely to sell it because I am a bass player primarily. I'll let you know.
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Sounds good. Keep me posted.
Thanks.