| Author | Message | ||
     Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
In the UK Im having huge difficulty finding replacements for the 20 uf / 25v caps in a "2275-130 EX" amp (115 HD one thirty). These 5 lurk on the driver board, where the trimpot sits in midst of. The size is the issue: I ordered 3x "f&t" but they're 30mmx12mm so too long to fit really, and also I dont know which 3 of the 5 are to recap. So I need to re-do this. Can someone tell me: are any of these 5 critical to the sound? or could they be happily replaced with decent but generic as-close-as-I-can-find types ??.. ..such as for eg (the nearest I can possibly find after hrs of searching) http://www.ebay.co.uk/itm/MAL203036229E3 -Vishay-BC-Components-Capacitor-22Uf-25V -/360675934856?pt=UK_BOI_Electrical_Comp onents_Supplies_ET&hash=item53f9f60288#h t_3315wt_1120 thanks B-Jilm | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
As I cant add a photo on here Im unable to figure out which of the caps on this driver board is which: C34, C35, C36, C42 and C43. I can get a rough 'laymans guess' at which from the schematic might be more critical to the sound, and therefore which to choose from the 3 large 20 uf I have to recap, and which 2 remainders I leave be. But if anyone can tell me which is which: so with the board as I look at it -from the back/rear of the amp- I have cap.1 bottom left hand side, and cap.2 and cap.3 side-by-side above it (slightly to cap.1's right hand side). Then twds the middle of the board there is cap.4 above the trimpot. Lastly cap.5 twds the right hand side. if anyone can help me ID C34-C43 Id be really grateful. (Or ideally just point and tell me 'do that one/that one/that one, leave those two')........ fab. thanks B-jilm. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
You CAN post a pic here directly. Go here: http://www.pacair.com/discus/messages/20 /20.html?1367290987 put the line shown EXACTLY as it is shown here in your message somewhere. It will prompt you as you post your message WHEN to load the pic. Do NOT change ANYTHING in the line above. Do NOT type something in where it says "text description". As for the size of the caps, 20uF at 50v caps should be really small. I get them even from sprague sometimes and even they are plenty small. Xicons are very small as are the cheapies from weber. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Also, by the way, in that particular spot, you MAY be better off with radial caps. Might be easier to find small enough to fit. Mike. | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Ok Mike thanks Ill give that a try.. (Message edited by usermod1 on July 08, 2013) | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Ok Mike thanks Ill give that a try..  | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Mike my pics seems to be about 10x the limit (its a 10 yr old 3mp slr) so I cant attatch. I seem to inadvertantly added a link directly into my 'photo album' again, but the pic in Q seems to be there. Could you have a look, and then podssibly erase thos post, as you kindly did before? thank you,RC | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
The caps Ive bought (F&T 20 uf/ 63v, the closest I could find on any site bar the cheapy ones I linked to above: Ive got 2 on their way of these so its a Q of which ones I put where on the DB-2 board you see). | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
The caps Ive bought (F&T 20 uf/ 63v, the closest I could find on any site bar the cheapy ones I linked to above: Ive got 2 on their way of these so its a Q of which ones I put where on the DB-2 board you see).... ...are quite big @ 32mm x 10mm. But I'll have to use them, on a 'titanic' tilt i guess or upright. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Here's your picture  | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Aha- cheers alot for that. Ok so this is the driver board, with the bias trimpot in middle (afaict). Pls ignore my red markers: just for the pic ie polarity ID on recapping. Ok what I want to do is establish which 3 are the most critical of these 5 blue 20uf 25v caps. Thats all. Btw I think why my 3 22uf's are physically larger is due to them being 63v (only quality f&t low voltage axials close to 20 uf I could find). | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Actually, they are all pretty damned important for the driver circuit to function properly. C34, c33 and c36 are used as a coupling cap. The other two are critical for the power driver section. Mike | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Ok when you say 'the other two' which two do you mean? (even looking at the schematic and following tracks I find it nr impossible to tell which is C* and which is C*). So if I have two of a kind and three of a kind, maybe use my two (smaller) 22uf's for your 'other two', and the remainder C*, C* and C* 3 my f&t larger 22uf's? | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Or can anyone say which on my pic is which? ie Cap btm LHS is C* Cap "pair" above are: Top C* and Below it C* Middle cap nr trimpot is C* Cap RHS is C* Thanks alot! b-jilm | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Can anyone help me with this? Thanks, B-jilm | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
Give me some time and I will try to find a DB2 board and see what's what. MIke. | ||
| Mike Kaus (mm210) Username: mm210 Registered: 05-2006 |
OK-let's try this. I made it as big as I could. Pay no attention to a few of the resistors on this board. This is an EARLY DB2 that was intended for the SS upgrade in the field. Some of the resistor values are different but the bulk is the same.  | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
You are a very nice man Mr. Mike. That has just seconded exactly my latest figuring these pesky caps out (now Iknow the opamp chip is LM1458.. not as I read the ink splodge on the schematic, as LMM58!! no wonder I was confused!). So the 'pair' you referred to are C42 and C43 right?? and the other 3 are coupling caps? cheers rc | ||
| Rory Coupland (bigjilm) Username: bigjilm Registered: 06-2013 |
Yes- c34,c35,c36 couplings caps / Ive just found the answer in yr reply above ^ 4 or so. Appreciate your time Mike. Recap now can be completed / Over & out for this thread. |