AR-5 ?

[DavidDru]

I had a few other AR's jump into the mix so the 5's are still waiting warmer weather and their color coat. Now after adding the 6's to the top of the stack I'm am noticing how weak the 5's tweeters have become.

I guess I need to track down a test cd and sound pressure level meter to be more specific about the problem.

Looks like tweeter replacements are in order sometime this year.

Or maybe Roy can service them back into form?

[owlsplace]

Proposed addition to the AR-5 arsenal

They have been on CL at $300 for quite a while. They have been messed with so I wasn't too interested even though they were local. Never seen dark grill cloth on US production before but I can't make out the details on the labels in the photos. They have the Norwood style back labels.

Currently on the auction site. We'll see how high they go ...

If I am unopposed they will make pair #3 -- still working on the other two

Roger

[Aadams]

I had a few other AR's jump into the mix so the 5's are still waiting warmer weather and their color coat. Now after adding the 6's to the top of the stack I'm am noticing how weak the 5's tweeters have become.

I guess I need to track down a test cd and sound pressure level meter to be more specific about the problem.

Looks like tweeter replacements are in order sometime this year

The tweeters in the 5 only cover the Freqs above the mid range. It should sound weaker on most music. Can it be your ears?

Adams

[RoyC]

Proposed addition to the AR-5 arsenal

They have been on CL at $300 for quite a while. They have been messed with so I wasn't too interested even though they were local. Never seen dark grill cloth on US production before

Roger

Roger,

What has been done to them? The cabinet edges look good, and the cloth is original.

You may be able to coax more output from your AR-5 tweeters by very carefully scraping away the butyl rubber coating over the voice coil gap.

Roy

[VintageMan]

Has this dark cloth been used on later series of the AR3a?

[owlsplace]

I had a few other AR's jump into the mix so the 5's are still waiting warmer weather and their color coat. Now after adding the 6's to the top of the stack I'm am noticing how weak the 5's tweeters have become.

I guess I need to track down a test cd and sound pressure level meter to be more specific about the problem.

Looks like tweeter replacements are in order sometime this year

The tweeters in the 5 only cover the Freqs above the mid range. It should sound weaker on most music. Can it be your ears?

Yes, definitely could be/is my ears ,,, maybe could use an esr resistor tweek on the mid-ranges since I used a bank of Madisound surplus caps in these.

Roger,

What has been done to them? The cabinet edges look good, and the cloth is original.

You may be able to coax more output from your AR-5 tweeters by very carefully scraping away the butyl rubber coating over the voice coil gap.

The pots were bypassed and the woofers refoamed. The seller isn't showing the drivers so ??? Some of those tweets that I've seen don't seem to have much if any of the gap sealant applied others are totally sealed. Definitely worth removing it if it gains some output.

Roger

[RoyC]

Has this dark cloth been used on later series of the AR3a?

If by "later series" you mean 3a's with foam surround woofers, yes.

[VintageMan]

If by "later series" you mean 3a's with foam surround woofers, yes.

OK, I was told that the owner had done this.

I will put up some photo's.

[owlsplace]

Proposed addition to the AR-5 arsenal

They have been on CL at $300 for quite a while. They have been messed with so I wasn't too interested even though they were local. Never seen dark grill cloth on US production before but I can't make out the details on the labels in the photos. They have the Norwood style back labels.

Currently on the auction site. We'll see how high they go ...

If I am unopposed they will make pair #3 -- still working on the other two

AR-5.ebay.01.jpg

Roger

Okay, no one else wanted them It will be fun lighting up three sets of 5's and 6's at the same time...

[stupidhead]

Okay, no one else wanted them It will be fun lighting up three sets of 5's and 6's at the same time...

congrats

[Aadams]

It will be fun lighting up three sets of 5's and 6's at the same time..

An opportunity for a modular LST2 perhaps.

[owlsplace]

It will be fun lighting up three sets of 5's and 6's at the same time..

An opportunity for a modular LST2 perhaps.

Yeah, like playing with an "Erector" set ... let's see, can add the ADS 12" woofers in using the bi-amp feature ... maybe a delay circuit for the 6's

[owlsplace]

So I picked up the auction site acquisition this morning. I kind of expected that they had been monkeyed with so I wasn't surprised.

September 1973 production, cabs not too bad to look at, grills are decent without badges.

Generic foam glued to back of cone. Will need to replace that.

The pots were bypassed and one of the crossover boards had been popped off and reinstalled using wall anchor screws.

Pots actually were nice although one wiper was missing. I clean them up and put some Caig Cromolux on them, swiped a wiper from a spare pot and rewired the crossover.

Finally got a set with Sprague Compulytics.

Drivers looked decent.

They all ohmed out well.

Reattached the board and sealed it using black silicone and three roofing screws with washers for positioning. I don't think it will be coming off again.

I measured everything except the coils. The Compulytics came in at 4.4, 26.9 and 77.7mfd and given the recent discussion on capacitance meters I would say they are right in the ball park.

The resistor wire ohmed out at 1.5. See photos for resistance on the drivers vc's. The fiberglass stuffing weighed in at 26 ounces.

Paired this one against a speaker from the earlier rebuild in this thread and the upper range sounds significantly better listening to a Sheffield jazz recording at this late hour.. Is it the caps? The previous rebuild used Madisound surplus and Carli's.

May get to the other speaker tomorrow. At least the crossover board wasn't popped on that one.

Roger

[Aadams]

Paired this one against a speaker from the earlier rebuild in this thread and the upper range sounds significantly better listening to a Sheffield jazz recording at this late hour.. Is it the caps? The previous rebuild used Madisound surplus and Carli's.

Maybe it is me but which speaker has the "better" upper range?

[ra.ra]

Too bad about the foam surrounds, but those are going to end up being a very fine pair of AR-5's.

You often do such a great job of cleaning the pots without removing them from the cabinet - - could you please describe your detailed process, and also explain this Cromolux product? Thx.

[owlsplace]

Paired this one against a speaker from the earlier rebuild in this thread and the upper range sounds significantly better listening to a Sheffield jazz recording at this late hour.. Is it the caps? The previous rebuild used Madisound surplus and Carli's.

Maybe it is me but which speaker has the "better" upper range?

The later one with the Compulytics. Ken Kantor's approbation doesn't really apply to this model since the original crossover design used foil caps. The caps may be a factor or it could be just the condition of the drivers, moon phase, what I ate for dinner, etc.

I'll be taking the OP speakers apart again to finish the cabs so I may experiment with some different caps or I may do it on pair #2 which is in the wings.

Too bad about the foam surrounds, but those are going to end up being a very fine pair of AR-5's.

You often do such a great job of cleaning the pots without removing them from the cabinet - - could you please describe your detailed process, and also explain this Cromolux product? Thx.

I usually cut the pots out but since the xover board was already separated on this it was simple to work on before reattaching it.

I think the Cromolux is an earlier version of "De-Oxit." I got if from an old friend who serviced TWA aircraft back in the day.

The pots are hit or miss depending on how pitted they are. The quality of the silverplating is where the issues arise. Plus there are three or more different metals used in the construction which equals electrolysis meaning the different metals begin moving around. Once the brass is exposed it forms an insulating coat of verdigris as the brass continues to oxidize. Add in temperature changes due to current flow, etc, and they eventually go into cascade failure mode.

If there is minimal oxidation I just scape any hard stuff off being careful not to just glaze it over, polish with Simichrome and use one of the contact CLP products to prevent further oxidation. I've been leery of using the automotive silicone grease on these pots as I have an open can of it and it became gummy after a few years. If the contact plate is heavily pitted it is abrasive time and you can say goodbye to the silverplating. I'd prefer to ditch the pot at that point since having to service them on a regular basis would be a bit of a pain.

I did get a pair of HK pots recently which I will try in a pair of AR-6's. They don't look bad and I'm sure they will outlast me. Someone should crank out some rebuild kits for the A-P pots -- ahh, but L-pads are inexpensive and easy and are probably a better choice all around.

Roger

[RoyC]

Paired this one against a speaker from the earlier rebuild in this thread and the upper range sounds significantly better listening to a Sheffield jazz recording at this late hour.. Is it the caps? The previous rebuild used Madisound surplus and Carli's.

Roger

Roger,

My money is on a stronger tweeter, which is more able to reach further down into the mid frequencies. The output of the original tweeters is all over the place these days.

Are the inductor values the same as your other pair? The earlier 5's had different inductor values than later 5's for the mid and woofer.

Roy

[owlsplace]

Roger,

My money is on a stronger tweeter, which is more able to reach further down into the mid frequencies. The output of the original tweeters is all over the place these days.

Are the inductor values the same as your other pair? The earlier 5's had different inductor values than later 5's for the mid and woofer.

Roy

I can go with tweeter. The number two set was slated for L-pad and Hi-Vi conversion. It has the earlier coil set. The other two have the later coil set. I also picked up an extras set of xovers with the later set of coils. The two separates I was/am listening to have the later coil set although on the 1973 set the coils are no longer marked.

Listening at moderate levels I can see why I really liked/like this model.

I did get into the other speaker from this set today although it is not finished yet. The mid pot was badly corroded which is probably the reason for bypassing all of them. Amazing how three pots can be in nice shape and one goes south. I replaced it with a spare. The Compulytics measured like the others -- good to go. The xover board had also been pulled from this cabinet previously so I pulled it again, At least they didn't drill holes through the back and use wall anchors. The xover is a lot easier to work on out of the box and I needed to refresh the acoustic seal. They were obviously never intended to be removed and are a bit of a pain to line up on the reinstall.

Just to satisfy my curiosity I removed the contact plate/disc from the bad A-P pot to see if the backside was usable but it wasn't. Just replacing the disc would probably bring most of these pots back to life if the wipers are still intact. I'll hang on to the parts. In all fairness to the original engineers these were never intend to last this long anyway.

Roger

[ar_pro]

Nice project, Roger - you're like an AR-5 magnet.

Have you considered using an AR-9 era tweeter as a replacement?

[owlsplace]

Nice project, Roger - you're like an AR-5 magnet.

Have you considered using an AR-9 era tweeter as a replacement?

Haven't considered that. Is it a viable option, size, etc? The Hi-Vi drops in with some minor tweeks to the xover.

[ar_pro]

I'm pretty sure that it's the same size.

Part #200029-1, as used in the AR-9, AR-90, and AR-91.

3/4" ferrofluid, 4 ohm only, rear connection.

They've jumped up a bit in price - they used to sell for about $75/driver, but it's closer to 100 bux, now.

Maybe AR-9 owners are buying them as insurance - I've never managed to blow one out, so who knows?

I'd be curious about the result, especially compared with the Hi-Vi 1 1/8" tweeter.

[owlsplace]

I'm pretty sure that it's the same size.

Part #200029-1, as used in the AR-9, AR-90, and AR-91.

3/4" ferrofluid, 4 ohm only, rear connection.

They've jumped up a bit in price - they used to sell for about $75/driver, but it's closer to 100 bux, now.

Maybe AR-9 owners are buying them as insurance - I've never managed to blow one out, so who knows?

I'd be curious about the result, especially compared with the Hi-Vi 1 1/8" tweeter.

Will keep in mind but when parts exceed the value of the speaker you are usually better off buying a better speaker model like the 303; however, it has possibilities as an ultimate tweek. I think that tweeter is also used in the 11's ... been seeing some fried 11 tweets on the auction site lately.

Not sure how to implement the four ohm tweets into an eight ohm design? I'd be willing to give it a go at some point though.

Update: I did refoam one of the woofers today with RoyC's favorite surround -- Boston FF. I see why he likes them. I put a JBL foam on one of the speakers from the OP which several people insisted was the best option but I'm going with the Boston FF foam from here out

Updated on 5/21: refoamed the other woofer -- making haste slowly -- this is the year of the classic AR's for me -- a 40-year reunion so taking my time to smell the roses ...

Roger

[owlsplace]

Norwood AR-5's are refoamed and back in service this evening. The first thing I did was blow both fuses on Telarc's 1812 Overture -- those darn cannon blasts. I'll save that recording for the ADS' ... at lease when I want the neighbors to take notice.

Cabs aren't too bad ... some plant stand damage on the tops to deal with.

I think I got the seal back on the crossover board ... a little extra RTV showing there that needs to be removed

One step closer to the AR 5-5-5 set up. Have to get the other set out of storage for rebuild. Meanwhile back to the 6's and the 7's will be making their way up from AZ shortly. Should be a busy year.

Roger

[owlsplace]

Back to the 1970 AR-5's that I put aside last year after grabbing them on the auction site initially for spare parts. Prepping the woofers for new foams yielded a little surprise. One of the cones didn't compress when pushed in, oops...

Now you know what a fried voice coil looks like. The other vc shows some discoloration from heat damage. There was enough current flowing to melt the adhesive around the lead in wires and around the dust caps.

Anyway, the challenge: I have a spare vc from a woofer with a bad cone so will see if I can make one out of the two. May need to tap RoyC's brain power on how to line up all the parts

Meanwhile back to getting the adhesive off the good vc without damaging anything ... glutton for punishment.

Roger

[owlsplace]

I'm pretty sure that it's the same size.

Part #200029-1, as used in the AR-9, AR-90, and AR-91.

3/4" ferrofluid, 4 ohm only, rear connection.

They've jumped up a bit in price - they used to sell for about $75/driver, but it's closer to 100 bux, now.

Maybe AR-9 owners are buying them as insurance - I've never managed to blow one out, so who knows?

I'd be curious about the result, especially compared with the Hi-Vi 1 1/8" tweeter.

I picked up a set of AR-TSW series tweets with dcr similar to the originals. Looks like the faceplates unscrew and then it would be necessary to mount them into an original AR-5 tweeter cup or something similar... be fun to try anyway and the price was right.

Roger