Capacitors -Help Please

[Mothman]

I have a 40yr old Sansui amp that I would like to get re-capped, however first step is to buy the caps but I’m not sure what type I need. Panasonsic FC’s seem to get recommended a lot but I’ve looked on Farnells website and many of the values I need don’t appear in their FC range. I have detailed below the quantities and values and have added the Farnells part codes for the FC’s where available, but I would be grateful if anyone could suggest alternatives for those items not in the FC range.

Aluminum Electrolytics Radial Leads
Qty x ufd / voltage – Farnells part code

14 x 1/50
4 x 10/16
4 x 47/6.3
2 x 47/16
2 x 47/50
2 x 100/6.3
1 x 100/50 - 1219478
2 x 220/6.3
1 x 220/25 - 1219468
1 x 220/75 or 100
2 x 470/16 - 1219462
2 x 470/35 - 1219475
3 x 4700/63 -

Bypass caps

2 x 15-25/100 polypropylene axial leads
1 x 10/100 polypropylene axial leads

Cheers:)

[DSJR]

Do the caps REALLY need changing? Are they bulging or leaking?

So much crap talked about electrolytics going off. Japanese made amps tended to have much better components inside than their European competition and, if the amp is working and sounding good still, I'd really be inclined to not fix what ain' t broken :)

[Mothman]

Dave when I got the amp it wasn't working, but someone cleaned it up and re-set the bias for me and it played well. However after a few months it developed distortion in one channel and hasn't been used since, I like the amp very much and therefore figured that if I was going to have to get it repaired again I may aswell get it re-capped in the hope it may stay trouble free for a period and possibly sound even better:).

[reddish75]

I now buy all my parts from digikey or mouser in the us, they have the full range of panasonic fc and fm's of which i would use the fm variant for the values you can get in it then for the rest fc's, for signal capacitors use elna silmic avalible as the elna rfs range from digikey any caps 1uf of smaller use Panasonic stacked film cap's. For non-polar use the panasonic su range.

When buying a radial lead capacitor, you are often given a choice between a short and wide cap, or a tall and thin one of the same value and voltage. The short and wide one will have a longer life and better specs, and probably fit better in vintage equipment considering the reduction in size of electro's over the years.

Regards

Chris

[Mothman]

Thanks Chris. I had a look at the FM range on the Digi-Key site and same problem many of the values I need are either not listed or are non stock items:(

[reddish75]

You can go up voltage ie original 16v, new 25v, at any rate the fm range is limited, as i said the ones you cannot find in fm go for fc, also the nichicon pw is their panasonic fc equivelent and the nichicon he is their fm equivelent.

[pete_mac]

You can go up voltage ie original 16v, new 25v, at any rate the fm range is limited, as i said the ones you cannot find in fm go for fc, also the nichicon pw is their panasonic fc equivelent and the nichicon he is their fm equivelent.

Sound advice above! I've restored many Sansui amps and I use the Panasonic FC or FM wherever I can. Look at the green Nichicon Muse BP caps or the Panasonic SU series for any bipolar caps. Elna Silmic II caps are nice signal path/preamp caps, but it depends on availability. I've also used FCs and FMs in signal path applications and they work fine.

Regarding the little 1uf 50V caps, look at replacing them with something like a Pansonic ECQ-V stacked film cap (1uf 50V or 1uf 63V) or an Epcos B32529 stacked film cap. Better performance than an electrolytic in this application. Out of the two, the ECQ-V are easier to fit due to longer leads.

http://uk.farnell.com/panasonic/ecqv1h105jl/capacitor-film-50v-1uf/dp/1744833

http://uk.farnell.com/epcos/b32529-c-105-j/capacitor-film-63v-1uf/dp/1692372


The Pansonic TU-P or TH-A series are very solid caps for power supply filtering and output caps, so see if they have anything suitable in these series. Are these caps PCB mounted or clamp mounted in your amp? PCB mounting can make things tricky due to different pin spacing of the capacitors. Worth looking into.

http://uk.farnell.com/panasonic/ecos1ja472ca/capacitor-4700uf-63v/dp/1198699

You may also wish to consider a larger 6800uf cap subject to the ability of the amp to support this.

http://uk.farnell.com/panasonic/ecos1ja682ea/capacitor-6800uf-63v/dp/1198554

I'm a strong advocate of recapping vintage amps if you intend hanging onto them and getting the best out of them sonically. I am yet to hear a vintage amp that has not been improved by recapping, whether a tiny AU-101 or a larger, more complex model. OF course the quantum of the improvements varies between amp to amp subject to the condition of the original caps. Moreover, it is good preventative maintenance, much like changing the timing belt on a car engine as opposed to waiting for the belt to snap and then rebuilding the entire engine ;)

Which exact model of amp do you have?

cheers
Pete

[Mothman]

Hi Pete, thanks for the detailed reply:). The amp is an AU-505 bigger brother of the Au-101. The amp impressed me whilst it was working and I feel it's to good to chuck away.

I don't have any DIY electronics skills myself and so the plan was to buy the parts (though this proving more complex than I at first thought) and then try to find someone to fit them. I have already managed to obtain a copy of the schematic\service manual which is a step in right direction.

Below is a link to a thread on Audiokarma which details a re-cap of this model and from which I pulled the list of parts, though I think you may have to be registered with the site for the pics to show.
http://www.audiokarma.org/forums/showthread.php?t=304159&highlight=au505

One question, are the caps in the signal path identifiable simply by their values?

[pete_mac]

Hi Pete, thanks for the detailed reply:). The amp is an AU-505 bigger brother of the Au-101. The amp impressed me whilst it was working and I feel it's to good to chuck away.

I don't have any DIY electronics skills myself and so the plan was to buy the parts (though this proving more complex than I at first thought) and then try to find someone to fit them. I have already managed to obtain a copy of the schematic\service manual which is a step in right direction.

Below is a link to a thread on Audiokarma which details a re-cap of this model and from which I pulled the list of parts, though I think you may have to be registered with the site for the pics to show.
http://www.audiokarma.org/forums/showthread.php?t=304159&highlight=au505

One question, are the caps in the signal path identifiable simply by their values?

Ah, nice one. They are a sweet-sounding amp!

I posted a recap/upgrade thread of the AU-101 a while back on audiokarma myself: http://www.audiokarma.org/forums/showthread.php?t=341428

The thread that you linked to seems to establish a nice restoration/modification pathway. Recapping is pretty straight-forward if you have a reasonable soldering iron and a solder sucker, but I can see the attraction in getting someone else to do it if you're not keen!

Regarding signal path capacitors, it is not always that simple - the schematic needs to be interpreted. I'd just replace all of the 1uf caps with the films as mentioned earlier and leave the rest as electrolytics.

Regarding the poly caps, the Vishay MKP1839 are a good option. For 4700uf caps you could easily stick to smaller caps if you wished. I've linked to the 4.7uf and 10uf versions below. IMHO a 4.7uf by-pass cap is fairly large in this application anyway:

http://uk.farnell.com/jsp/search/productdetail.jsp?sku=1413920

http://uk.farnell.com/vishay-roederstein/mkp1839610164/capacitor-axial-mkp-10uf-160v/dp/1413921

[Mothman]

I posted a recap/upgrade thread of the AU-101 a while back on audiokarma myself: http://www.audiokarma.org/forums/showthread.php?t=341428

You did a great on that AU-101:thumbsup:. The external condition of mine is OK to start with, the side panels need re-veneering which is no problem and the rest isn't too bad to say it's 40yrs old.

Thanks for all the help with the caps, hopefully I can now work out an order from your suggestions, it's much apreciated. As you say these are sweet sounding amps despite their lowly status and it would seem a crime to dump it.

[reddish75]

While your in there replace the domed transistors on the poweramp board they are known to go faulty, the big capacitors on the same board are signal path capacitors, most new ones will need new holes drilling through the circuit board to accommodate them, going up slightly in value with them will be fine, the main powersupply capacitors are a bugbear to replace as modern equivelents are alot smaller and don't have solder tabs on them, careful choosing of replacement caps i.e same diameter may take a bit of searching for quality caps and more often than not they will be 'snapin' caps that will not take multiple wires soldering on to them as the pins are quite short, the solution is to use those crimp on eyelets things you can find in almost any diy shop, crimp them then solder them, then solder the wires to the eyelet.

Chris

[DarrenHW]

Picked up one of these at the local car boot last weekend for £5. I liked the way it sounded from the second I plugged it in to test it and quickly swapped it for the Technics SA-200 I have in the kitchen (which coincidentally I bought from the same car boot last year for £5 as well). The Sui is more detailed and far more natural sounding, it lacks the sound stage of the Techie but the Sui's bass has far more oomph and is quite a nice pairing for the B&O RL60.2's I have hung on the wall. I needed to place an order from Farnell for the upcoming servicing of my Quad 405 but couldn't make it to the £20 order value for free delivery, having read some of the threads on AudioKarma and Seteo.net I looked into the price of recapping the Sui which was about £7 and it took my order value to £20.09, result!

The caps arrived yesterday and I've spent this morning recapping and cleaning the Sui whilst making Chicken Stock, which in a couple of hours will go on to become Chicken Soup to use up the last of my Sweetcorn harvest! It's the first time I've recapped an amp and really enjoyed the process, I was a little nervous about it having never swapped so many components at one time before but very relieved when I powered it on and nothing blew up! I'm currently "burning in" the new capacitors whilst my stock simmers away and enjoying what I'm hearing. The Sui's really responding well to rock, hip-hop and electronic which is great as this is music I enjoy but don't really listen to on my main system in the lounge.

I've had a great morning working on the Sui, making stock and looking forward to the change in season which will mean outside chores decline and I'll have the time to spend renovating the vintage equipment I've bought over the last year since joining AoS. In total I've spent £12 (or as I prefer to look at it £8 as if I didn't order the caps I'd have had to have paid the £3.95 delivery charge :)), have a good looking and sounding amp and even if it doesn't stay in the kitchen in will probably move on to the shed / gym (where rock is always the order of the day!). This is something I would not have done before finding AoS as I was completely ignorant to the world of HiFi (outside of What HiFi magazine :doh:) and the pleasure working on vintage equipment can bring, thank you for opening my eyes or should that be ears.

:grouphug:

[Puffin]

Nice one. What you need to is make a "light bulb" mains lead. This means that if there is a problem with any "bodging" the bulb will light (in varying degrees of brightness) to confirm there is a fault somewhere. It avoids you blowing components.

http://i73.photobucket.com/albums/i239/saxonsex/Lightbulbtester_zps6feb90f6.jpg

If the unit has a captive mains lead you could build the tester with a 13A socket on one end (rather than an IEC) and a plug on the other.

Edit: Forgot to say that it will light momentarily and then go out if all is well:)

[DarrenHW]

Nice one. What you need to is make a "light bulb" mains lead. This means that if there is a problem with any "bodging" the bulb will light (in varying degrees of brightness) to confirm there is a fault somewhere. It avoids you blowing components.

http://i73.photobucket.com/albums/i239/saxonsex/Lightbulbtester_zps6feb90f6.jpg

If the unit has a captive mains lead you could build the tester with a 13A socket on one end (rather than an IEC) and a plug on the other.

Edit: Forgot to say that it will light momentarily and then go out if all is well:)

I see :idea:. I had read in one of the posts about recapping the amp someone had used a light bulb to test it but didn't know what they were referring to, thanks for the knowledge :thumbsup:

[Marco]

Yo, dude, howz that valve preamp of Dunc’s sounding? :)

Marco.

[DarrenHW]

Yo, dude, howz that valve preamp of Dunc’s sounding? :)

Marco.

I'll tell you (or better come round) when the 405's up and running. All parts now ordered (hence the above project) just waiting on delivery, hopefully next weeks project.

[Marco]

Okies, look forward to that. What’s your first impressions though, and what did you make of Dunc’s set-up? :)

Marco.

[DarrenHW]

Okies, look forward to that. What’s your first impressions though, and what did you make of Dunc’s set-up? :)

Marco.

I liked it a lot! Loved his KEF's, will be keeping an eye out for a pair of those! Hearing the valve pre against his passive pre, I thought the passive was more transparent but I preferred the bass and twinkly bits from the valves. Great to hear it through his 405's (it is phase inverted) to get an impression of what it will sound like here, I'll definitely be following Dunc by mono blocking a pair of 405's. First time I've heard FBA on a decent system as well, great to hear what can be achieved when implemented properly. Thoroughly nice guy too, very helpful and happy to explain things at a level I could (just about) understand all in all a pleasure to meet him.

[Marco]

Excellent - I certainly concur with the last bit!

Looking forward to hearing your new amplifier combo, so gizza shout when you’re free :)

Marco.

[DarrenHW]

Excellent - I certainly concur with the last bit!

Looking forward to hearing your new amplifier combo, so gizza shout when you’re free :)

Marco.

Not as much as I am! I have a quiet week beginning 22/09 so hopefully sometime that week? Had a bit of a move around here, the AV cabinet is gone, both TT's will be spinning, Klotz MC5000 with MS Audio Rhodium-plated plugs throughout, it's slowly coming together!

:gig:

[Mothman]

Picked up one of these at the local car boot last weekend for £5. I liked the way it sounded from the second I plugged it in to test it and quickly swapped it for the Technics SA-200 I have in the kitchen (which coincidentally I bought from the same car boot last year for £5 as well). The Sui is more detailed and far more natural sounding, it lacks the sound stage of the Techie but the Sui's bass has far more oomph and is quite a nice pairing for the B&O RL60.2's I have hung on the wall. I needed to place an order from Farnell for the upcoming servicing of my Quad 405 but couldn't make it to the £20 order value for free delivery, having read some of the threads on AudioKarma and Seteo.net I looked into the price of recapping the Sui which was about £7 and it took my order value to £20.09, result!

The caps arrived yesterday and I've spent this morning recapping and cleaning the Sui whilst making Chicken Stock, which in a couple of hours will go on to become Chicken Soup to use up the last of my Sweetcorn harvest! It's the first time I've recapped an amp and really enjoyed the process, I was a little nervous about it having never swapped so many components at one time before but very relieved when I powered it on and nothing blew up! I'm currently "burning in" the new capacitors whilst my stock simmers away and enjoying what I'm hearing. The Sui's really responding well to rock, hip-hop and electronic which is great as this is music I enjoy but don't really listen to on my main system in the lounge.

I've had a great morning working on the Sui, making stock and looking forward to the change in season which will mean outside chores decline and I'll have the time to spend renovating the vintage equipment I've bought over the last year since joining AoS. In total I've spent £12 (or as I prefer to look at it £8 as if I didn't order the caps I'd have had to have paid the £3.95 delivery charge :)), have a good looking and sounding amp and even if it doesn't stay in the kitchen in will probably move on to the shed / gym (where rock is always the order of the day!). This is something I would not have done before finding AoS as I was completely ignorant to the world of HiFi (outside of What HiFi magazine :doh:) and the pleasure working on vintage equipment can bring, thank you for opening my eyes or should that be ears.

:grouphug:

Congratulations on the Sansui find Darren. Mine was £2 from a carboot sale but unfortunately the subsequent £220 in recap & repair bills means it's proved to be far from a bargain :lol: To my ears the AU-505 is a very good amp which pairs well with my Ditton 44's and certainly compares favourably with my other amp, a re-capped A&R A60. They are both very fine amps but the bass on the Sansui just shades it for me.

[DarrenHW]

£220 repair bill :eek:

The Sui did battle with the old Technics SA-200 I had in the kitchen this weekend. The SA-200's now en-route to the shed and the Sui's found it's new home in the kitchen with a Marantz CD63. I completely agree about the bass from the Sui, it's almost valve like, the amp has more than enough detail for kitchen duties and has a far more natural (or should that be neutral?) sound than the SA-200. I haven't plugged it into my 44's but did have it hooked up to a pair of 15XR's all day yesterday, this was a great combination but I really can't accommodate 15XR's in the kitchen :(.

I will continue to modify the Sui, next I'll install a decent power cable, remove all features of the amp I won't be using (phono stage, headphone amp, light, speaker switch and tone controls) rewire input and speaker wiring and cut some replacement hard wood sides.