AR6 freshening up

[chris_f]

I say freshening up because I bought them for my daughter and she doesnt want them "restored", she wants them to stay "vintage". So I am leaving the cabinets and grills as is but need to clean the pots and would like to replace the caps while I am in there. My question is what is a good source and brand of capacitors to use in these? I dont want to buy just a replacement for it, would like to get something that will last and wont take away from these. I actually have two sets of these, the others I havent made up my mind on restoration but would like to at least rebuild the crossovers in those as well. 

Thanks!

[ar_pro]

Parts Express would have a nice selection for re-capping your AR-6.

 

[DavidDru]

PE will also have the nice sealant strip stuff to make sure you get a good seal on the woofer when you put it back on.  If the pots cant be cleaned, they will also have the LPads.

[JKent]

I haven't worked on the AR-6 but according to this post early ones had a 10uF cap while later ones had a 10uF and a 24uF

Asking "what brand" is opening up controversy but you want something that will last, so use film caps. They can be Dayton or Solen brand, sold by PE as AR-Pro suggested or go to Madisound and look at Carli and Surplus caps, or try Erseaudio and check out their PEX or Pulse X. Most of us here agree that more expensive does not mean "better" and any of these will do well. In fact, I believe it was Roy who noted that mylar film caps like the Carlis have an ESR closer to the originals and are therefore more authentic as well as being cheaper.

David makes good points concerning PE. Their foam gasket strip is excellent and they have cheap L-pads that are very good replacements for the troublesome pots (be sure to consult the AR-3a restoration booklet in our Library regarding pots).

Kent

 

[owlsplace]

Well, pick you crossover and get some film caps, Carli, etc. from Madisound ...

There are three sets of AR-6's here: two Euro's and one Unfinished Pine. I think two or maybe all three crossover variations are represented.

Roger

[chris_f]

Awesome! That is exactly what I was needing to know. I have downloaded the AR3 restoration guide and it have read through it several times now. I have just recently gotten back into hifi audio and have developed an interest in vintage gear. This is actually the first set of ARs I have owned and the first set I have attempted to recondition. As far as the L-pads go I was reading that some have noted that it changed the sound, any basis for that? Could it be that it just sounds different because the pots were old and word out? I only wanted to break these open once so I guess I should order the LPads just in case the pots cant be cleaned but would like to stay as close to original as possible.

[DavidDru]

The LPad description starts at the bottom of page 14 in the manual and calls for the addition of the 25ohm/10w resistor to make it perform more like the pots did.  I do not think you will find too many on here that feel the sound changes when using the LPad.  In fact, some think that as those tweeters have gotten older they could actually use a little less resistance and thus leaving the resistors off are an option on those.  I did in my AR3's and am happy about it.  Most fret about it simply because it isn't original.  

[owlsplace]

11 hours ago, chris_f said:

As far as the L-pads go I was reading that some have noted that it changed the sound, any basis for that?

The original design allowed the crossover frequency to vary as the pot was adjusted but I haven't tried to A/B them to see if there was any qualitative differences nor have I bothered to do the math on the frequency variations.

The final crossover was about as simple as you can get with few if any complaints.

Roger

[chris_f]

Thanks. Any reason to replace the resistors or coils or just the capacitors usually do?

[genek]

The coils are fine. As long as the resistors don't show any sign of physical deterioration, they're fine too.

[chris_f]

Great thanks guys. Plan on placing an order sometime this week. Will let you know how it goes.

[ra.ra]

Hi Chris. Cannot tell if you are located in the USA, Europe, Australia or Timbuktu, so it's difficult to recommend a specific cap product. However, since you do mention the pot control, we should assume you have the "A" version (with two coils) shown in Roger's post, and that version does indeed use only a single 10uF cap in each cabinet. Is your second pair the same version? 

Aside from the 16 ohm pot control, the only "resistor" in that circuit is the small, rigid Nichrome wire, and (in the completed project) that should remain "as is". I really like this early AR-6 version, but it's been my experience that this Nichrome wire makes this a very difficult instance of cleaning the pots, particularly if you wish to remove the pot from the cabinet. The reason I say this is because one end of this NiCr wire is soldered to the #2 pot tab, while the other end is tightly bound to the masonite panel with a hidden rivet shared by a green tweeter wire and a coil wire. (Aaargh.....why couldn't they have used an accessible screw connection?) This wire is very stiff and has no slack, and becomes quite difficult to unsolder and disconnect from the pot.

Maybe you can show pics of your crossovers? Perhaps this pic can illustrate my point about the NiCr wire connections.