Rta12-c schematic?

Mr. Sharpe

I'd like to recap mine and I need a list of the caps needed please. I notice the 12b is listed in the schematic thread but not the c, are they the same?

pitdogg2

I don't get this you have the speakers right? Why not look at the crossover and BAM you have the values of the caps and resistors needed....

Mr. Sharpe

Yes I do, but experience tells me the yellow caps don't have uf values written on them do they?

Mr. Sharpe

I'm not seeing values written on the yellow ones unless they're covered up. I can plainly see the inner caps (27uf) no sweat and resistor and all resistors on the top board, some of the caps I can't see, I don't want to start taking them off because then I won't have speakers to listen to while waiting on cap deliveries

pitdogg2

does the cap have ANY writing on it what so ever you can see? if so take a picture we will tell you. it also could be under the cap against the board. It will have a value somewhere. I promise.

Well you could take it off and put back on I have done that a bunch of times.

Mr. Sharpe

There's one of He yellow ones that has 4.4j 100v

Others are more 27's and a 5.5uf. You were right it isn't rocket science:) but the 4.4j I'm confused on.


Once the yellow ones are cleared up I think they're film caps right? Is the blue something special? I don't want to replace any of them and mess up the speakers or anything

F1nut

The yellow caps are mylar, the blue is an electrolytic. Nothing special about any of them.

The value is 4.4 uF, J is a code for the +/- tolerance.

As long as you've been here I'm surprised you don't know this stuff.

Faustin

I believe the 12b revised schematic is the correct one for the 12c. The revised has a poly switch instead of a fuse for the tweeter.

Mr. Sharpe

F1nut wrote: »

The yellow caps are mylar, the blue is an electrolytic. Nothing special about any of them.

The value is 4.4 uF, J is a code for the +/- tolerance.

As long as you've been here I'm surprised you don't know this stuff.

I didn't know what the J was for, my old cv's had three of those and didn't know those were uf values

pitdogg2

keep in mind that the new film caps will be much bigger. you will need to be creative.

Mr. Sharpe

Haha yeah I know, I saw where someone on here used sonicaps for his rta12 sprakers and he had to use two caps for the 5.5uf, I mean I'm cool with doing that but I think his upgrade cost something like $300 and that's quite a bit more than I'll spend. I still have several Dayton caps left from when I was going to recap my jbl speakers and I'm thinking I may use this but not sure yet.

Mr. Sharpe

Anyway so sonicaps are probably not happening on Thai upgrade what other brand makes a good cap would you recommend besides clarity of course unless they have a "cheap skate" series:) stolen, Dayton I know Mundorf is highly regarded and jantzen

Faustin

If you don't want to spend the money for all Sonicaps, I would recommend going with a Sonicap Gen 1 or Clarity ESA for the high pass and then use the lesser expensive brand for the low pass. That is what I did on my 12's and once everything burned in they sounded fantastic.

Mr. Sharpe

Okay I'll look into it

Mr. Sharpe

I have a question about the safety switch on top, looking at the schematic I wanna say it's a 3/4a fast blow? And what about these

What are they and will they need replacing?

pitdogg2

Looks like 750pf silver mica cap. If so those are used as bypass cap. They get tossed in most cases. You may need to use a jumper in the circuit. ATM I'm not positive. I do not have access to the schematic.

Mr. Sharpe

Okay, I don't mind using a jumper as long as these aren't needed. I saw mica on the schematic and had never heard of that

pitdogg2

Like i said I'm not positive you will need a jumper. With better caps those are not needed.

Mr. Sharpe

Good I'll toss em then. I'm gonna dish out for the sonicaps on the top may as well, I do have one more question then I'll leave you alone, I'm getting most items from soniccraft and it doesn't look like they carry safety switches, I'm guessing there aren't any alternatives for these huh?

pitdogg2

Why on earth would you want them? They're a problem, stick a .5 ohm 12 watt mills resistor in its place and feed the speakers good amplification.

westmassguy

Mr. Sharpe wrote: »

Okay, I don't mind using a jumper as long as these aren't needed. I saw mica on the schematic and had never heard of that

Good heavens NO. Do not jumper them, just remove them. They're no longer needed with quality Metalized Polypropylene Capacitors

Mr. Sharpe

pitdogg2 wrote: »

Why on earth would you want them? They're a problem, stick a .5 ohm 12 watt mills resistor in its place and feed the speakers good amplification.

They have 300 watts and I was just askin sheesh

westmassguy wrote: »

Mr. Sharpe wrote: »

Okay, I don't mind using a jumper as long as these aren't needed. I saw mica on the schematic and had never heard of that

Good heavens NO. Do not jumper them, just remove them. They're no longer needed with quality Metalized Polypropylene Capacitors

Simple enough

Mr. Sharpe

So after doing some reading in some old threads am I to understand the "5.5uf" is a 55uf capacitor? I'm not at home right now so can't look... dear oh dear hahaha think I almost screwed up ordering caps to make the 5.5 value haha yikes

Mr. Sharpe

I guess the people at work were right, I am blind

westmassguy

2 X 27uf will do nicely

Mr. Sharpe

I gotcha thanks to all. Due to budget constraints I think I'll end up using daytons, I can't afford all of those sonicap 27's

Mr. Sharpe

I've put in all the Dayton 27uf caps onto the low end side of the speakers, I figure since I already purchased the 4.4uf sonicaps I'll be getting four 27uf sonicaps for the high end. I'll upload progress all in one comment since it's been a while since posting here. Should be within the week maybe.