Tascam M-308B, M-312B, M-320B PARTS!

sweetbeats

sweetbeats

Reel deep thoughts...
I'm parting out a Tascam M-308B. Rouh on the outside, super clean on the inside. Many of the parts are completely compatible with the non-'B' series 300 mixers.

It goes like this:

  1. PM me
  2. Tell me what you need
  3. I'll tell you if I have it
  4. You make me an offer
  5. We come to terms so I can get the thing off my workbench

:)

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Still have a bunch of parts

Any reasonable offer welcome...channel cards, buss cards, faders, knob and switch caps...ooh-ooh.
 
Tascam parts

Hi , I'm wondering if you still have the small gain knobs on the bass and mids EQ pots? If so , are they the same as used on the M320B and if they are....How much for the knobs? I need several....probably all of the ones on this mixer. Just e-mail me and let me know at mogumbey@gmail.com Thanks!
 
sweetbeats said:
Still have a bunch of parts

Any reasonable offer welcome...channel cards, buss cards, faders, knob and switch caps...ooh-ooh.
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Hi,
I know it's been a while since you posted that you had parts available from your Tascam 308 but I was hoping you still had a square tan button and a small orange variable knob from the tone stack.
Thanks
Jim
 
IFixAudio said:
Hi,
I know it's been a while since you posted that you had parts available from your Tascam 308 but I was hoping you still had a square tan button and a small orange variable knob from the tone stack.
Thanks
Jim
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Jim,

PM me. I’ll look for your message. Thanks.
 
Hi there! You wouldn't still happen to have the power transformer would you? That would be incredible!
 
Sorry, I’m new here as well, not sure how to PM someone either haha. My email is Nate_sk8_8 (at) hotmail.com

Or you can PM me on here! Thanks!
 
sweetbeats said:
Still have a bunch of parts

Any reasonable offer welcome...channel cards, buss cards, faders, knob and switch caps...ooh-ooh.
Click to expand...
Hey Sweetbeats, not sure if you saw my last posts in the thread, hopefully replying to one of your posts sends you a notification.

Is there any chance you have a power transformer for an m-308? Thanks :)
 
NateF said:
Hey Sweetbeats, not sure if you saw my last posts in the thread, hopefully replying to one of your posts sends you a notification.

Is there any chance you have a power transformer for an m-308? Thanks :)
Click to expand...
Hi. I got a notification from your quotation of my post. I think I do. But is this for a 300, or a 300B? I ask because I’m wondering if you also need the phantom power supply transformer, or just the main transformer?
 
sweetbeats said:
Hi. I got a notification from your quotation of my post. I think I do. But is this for a 300, or a 300B? I ask because I’m wondering if you also need the phantom power supply transformer, or just the main transformer?
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Amazing!! Mine is just a M-308, no B. So just the main transformer for me!

Shoot me an email and we can arrange payment and shipping and such! Thanks so much!!
 
So first of all though I don’t want to go spelunking for the transformer (i.e. I’m *pretty* sure I have one but I *just* moved and can’t say I know exactly where it is…:)) until we can establish you need it. I’m not questioning you, I just don’t have the back story and have no interest in selling you something you don’t need. So…what’s going on with your M-308? Transformers don’t usually go bad unless something crazy went down.
 
Hey, of course! I really appreciate it!

So the story is I just got this from a guy on marketplace, listed as non functioning, for $30! Been dying to step up my M-216 + Tascam 48 setup to an M-300 series, so Im psyched! (Perfect world it would’ve been a M-312, but we can’t have everything, haha) Cosmetic shape is pretty good too.

He said he’s had it for years and it worked great. Also said it’s broken in the past (vague I know, unfortunately I was in a rush and I couldn’t get into the details), but he’s brought it to his tech and has had it worked on and fixed. I always get worried when someone says something’s been worked on in the past, cause you never know the quality of work that was done. Anyways, he said he was using it one day and it basically started smoking or he started to smell a burning smell, and it died.

He actually told me the power transformer is fried, so I’m guessing he had brought it back to his tech and that’s what his verdict was.

Anyways, I took it home, downloaded the manual and opened it up. It looks really clean inside. Looks like some caps were replaced on the power supply board at some point. Was half expecting to see a burst cap or something obviously wrong, but everything looked ok on quick overview.

I decided to quickly turn it on and measure the transformer secondaries, before the fuses. They all slowly vacillate around 1v ac. So, very off spec.

I know power transformers don’t typically go bad, so I’m not sure exactly what happened to it. I did notice in the schematic there’s no fuse before the transformer, only on the secondaries. Those fuses all look fine. Maybe there was a big power surge or something and it cooked the transformer? Can that happen? I don’t really know. I only had the power on for a minute at most when I tested it, and there was a bit of a burnt smell coming from the PT afterwards…

What do you think?
 
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Thanks for the background. Yes a significant surge could damage a transformer…any over-voltage/over-current situation could potentially damage electronic components.

Fuses on secondary side of a power transformer protect everything downstream of the transformer. They are current dependent and it makes sense to put them on the secondary side where the stepped-down AC rails are isolated by the transformer. So the fuses you see have nothing to do with protecting the power transformer from some massive over voltage or current situation. That’s what a surge protector is for. The power transformer can handle much more current than the device can demand, plus that demand is fused anyway. But that’s to protect everything downstream of the fuse, Anyway, it’s a bit baffling what might have happened, but if something causes enough heat in a transformer the varnish on the windings can break down causing leakage between windings, making more heat, and away we go.

Do this though, let’s make sure what you’re smelling is the transformer for sure…pull all the fuses to isolate the transformer and then power it up…if you smell hot electrical or see smoke shut it off. Proceed at your own risk, I’m not liable for any damage to you or your equipment, I’m only making a suggestion for a way to verify the transformer is roached, you acting on the suggestion is up to you. But if you do, report back.
 
sweetbeats said:
Thanks for the background. Yes a significant surge could damage a transformer…any over-voltage/over-current situation could potentially damage electronic components.

Fuses on secondary side of a power transformer protect everything downstream of the transformer. They are current dependent and it makes sense to put them on the secondary side where the stepped-down AC rails are isolated by the transformer. So the fuses you see have nothing to do with protecting the power transformer from some massive over voltage or current situation. That’s what a surge protector is for. The power transformer can handle much more current than the device can demand, plus that demand is fused anyway. But that’s to protect everything downstream of the fuse, Anyway, it’s a bit baffling what might have happened, but if something causes enough heat in a transformer the varnish on the windings can break down causing leakage between windings, making more heat, and away we go.

Do this though, let’s make sure what you’re smelling is the transformer for sure…pull all the fuses to isolate the transformer and then power it up…if you smell hot electrical or see smoke shut it off. Proceed at your own risk, I’m not liable for any damage to you or your equipment, I’m only making a suggestion for a way to verify the transformer is roached, you acting on the suggestion is up to you. But if you do, report back
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Cheers! Yep, I get that the fuses on the secondary side are for protecting the circuits downstream, not the PT. I think it is evidence that the PT got fried though, and that if it was a surge it must’ve somehow been powerful enough that it killed the PT before the surge made it through to blow the fuses on the secondary side.

I pulled the fuses out and had the power on for about 5 minutes. Nothing started smoking thankfully. I tested the secondaries again, this time on the transformer side of the fuse holders, and I wasn’t reading any voltage coming through. I had the power supply pcb unscrewed last time, and was testing the solder pads of the secondary leads instead. Don’t know why I was measuring a tiny bit of voltage last time vs now.

I also checked for continuity of the fuses for the hell of it while I had them pulled out, and they all checked out fine.

Turned off the power and smelled the PT. It smells melty. It definitely seems to be the source of the smell. I was sniffing around and everything kinda smells like that now, but the PT smells the most!

I did notice the power supply pcb smells the second most out of everything, but I think that’s probably because I have the mixer on its back right now, so the power supply board is directly above the PT, so it’s basically getting smoked from the PT below.

I definitely will go over the power supply pcb before I wire in a new PT, to make sure the caps are all correct values, installed correctly, and still good. But the PT seems to be the main issue at the moment
 
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