AR-2ax Project

[Michael T]

Yes, thank you Roy. I hope I didn't sound ungrateful for your input. You seem to be very well respected here and I give you that same respect.

It took me a bit too long to discover when asking for assistance or opinions, that even when there is empirical data, there is still various forms of bias whether it is brand loyalty or sound preference. I'm sure that if this becomes a hobby for me I will learn my own tricks and preferences.

In case it is not obvious, not only am I new to restoring speakers, I have not used a forum before other than for simply looking for info and Google leading me into one, never starting my own thread.

[stupidhead]

he is the man

 

[RoyC]

6 hours ago, Michael T said:

Yes, thank you Roy. I hope I didn't sound ungrateful for your input.

Not at all, Michael. I was more concerned with your apparent frustration with some aspects of the discussion, and wanted to assure you that the many nice restorations being done by CSP members are largely not the result of special electronics or speaker design knowledge on their part. I'm willing to bet your 2ax's are going to be just fine.

Roy

[GD70]

9 hours ago, RoyC said:

Not at all, Michael. I was more concerned with your apparent frustration with some aspects of the discussion, and wanted to assure you that the many nice restorations being done by CSP members are largely not the result of special electronics or speaker design knowledge on their part. I'm willing to bet your 2ax's are going to be just fine.

Roy

Roy, you described me to a T! LOL!

This is why I'm on the forums, to learn from all you gents!

[Michael T]

I do have one very critical question, and this goes specifically to stupidhead, why the name? It's a bit self-deprecating, is it not?

[stan461]

Michael T.

Do you have a list of the parts you ordered from Parts Express? I have opened up my AR2Ax's and might as well replace the caps & pots. I know you have done all the legwork but if you would share it would be greatly appreciated.

The reason I opened up the speakers was because of a scratchy pot that keeps dropping out. I thoroughly cleaned all the pots a couple of years ago but here we go again. Pots are the bane of many an AR speaker owner. 

Thank you, good luck and a healthy Happy New Year (whether you provide the info or not).

 

[Michael T]

59 minutes ago, stan461 said:

Michael T.

Do you have a list of the parts you ordered from Parts Express? I have opened up my AR2Ax's and might as well replace the caps & pots. I know you have done all the legwork but if you would share it would be greatly appreciated.

The reason I opened up the speakers was because of a scratchy pot that keeps dropping out. I thoroughly cleaned all the pots a couple of years ago but here we go again. Pots are the bane of many an AR speaker owner. 

Thank you, good luck and a healthy Happy New Year (whether you provide the info or not).

 

I will absolutely share any information I have although for the most part my information is limited. This however I know for sure 

I got 4 L-pads Part # 260-248, 2  25ohm 10 watt resistors Part # 004-25. These were from parts express. About $32 shipped.

I got my capacitors from madisound. 2 Carli MET 3.9mfd and 2 Carlo MET 6.0mfd. These were $11 shipped.

The AR-3A restoration guide will show how to wire these up. The one difference is that Roy C. recommends using the 25ohm resistors only on the mids not on the tweets (this is why I got 2 not 4).

I will gladly answer any other questions, if I can, I do have a BA in electronics engineering so I can handle crossover stuff.

Happy and safe new year to you as well.

[RoyC]

1 hour ago, stan461 said:

Do you have a list of the parts you ordered from Parts Express? I have opened up my AR2Ax's and might as well replace the caps & pots. I know you have done all the legwork but if you would share it would be greatly appreciated.

Stan,

if you prefer purchasing from one source the capacitors can also be purchased from Parts Express:

https://www.parts-express.com/dayton-audio-dmpc-40-40uf-250v-polypropylene-capacitor--027-421

https://www.parts-express.com/dayton-audio-dmpc-62-62uf-250v-polypropylene-capacitor--027-427

Before the geek squad weighs in, the 2ax  level controls more than compensate for any differences in ESR of the caps, and the difference between a 5% tolerance 6uf cap and 6.2 cap for this application is insignificant. Electrolytic capacitors of the appropriate values can also be used.

Roy

[Michael T]

1 hour ago, RoyC said:

Stan,

if you prefer purchasing from one source the capacitors can also be purchased from Parts Express:

I looked this route myself, thinking I could save on shipping. I don't remember exactly what I came up with but the ultimate price difference was minimal (perhaps favoring buying caps from madisound) and since someone had recommended the carli's (based on something some guy named Roy had once said) I went that route. You can check the numbers yourself and make your own decision on this, Stan.

1 hour ago, RoyC said:

Before the geek squad weighs in....

A couple of thoughts:

First, I thought you were the leader of the geek squad, LOL. I only say this out of pure respect.

Second, isnt that an invitation, to some, to chime in  I say this tongue in cheek, but maybe some truth?

Cheers

[Michael T]

Is it safe to use brasso cleaner on my ARinc badge? I actually went ahead and used a bit and I got a bit of black on the rag. I wasn't sure if it was dirt or black from the lettering, so I quit. 

[stupidhead]

2 hours ago, Michael T said:

I do have one very critical question, and this goes specifically to stupidhead, why the name? It's a bit self-deprecating, is it not?

Hey Michael, thanx for asking. You are not the first to ask either.

I adopted the name many years ago for a variety of reasons, mostly because I believe it to be a disarming moniker in a forum setting. Not remembering where I first heard the phrase but it was some 3 decades ago at least. I am also a deadhead which seems all too cliche' but in my way of thinking it is somehow related. My wife and I are also big Ratdog fans and go by ratdogheads in many circles. In fact that is our handle on facebook!

Not intentionally self-deprecating but I can certainly understand that as a conclusion one might draw.

Geoff

[Michael T]

they came ~happy dance~

[Michael T]

One concern though, when I push down on them they bottom out, quite easily. I guess that is because the cloth surrounds aren't springy like foam or rubber surrounds?

[genek]

26 minutes ago, Michael T said:

Is it safe to use brasso cleaner on my ARinc badge? I actually went ahead and used a bit and I got a bit of black on the rag. I wasn't sure if it was dirt or black from the lettering, so I quit. 

You should not use abrasive cleaners on printed logo plates. Abrasives are ok on the embossed, brown-lettered plates. Brasso makes a non-abrasive liquid cleaner called Gadget Care you can try (it's advertised as a cleaner for cellphone and other screens), but if there's any pitting on the surface, you're probably better off just ordering some repro badges.

[Michael T]

Another possible issue I found, the spider on both of the speakers seems to not be attached to the frame. It looks like it is attached to a masonite ring but the ring is not attached to the frame.

[GD70]

Just repilied in your AK thread, but I'll respond here as well. It's common for the Masonite rings to come loose, both for the spiders, and the woofer surround rings.

Carefully reglue the ring in its exact location, and checking that there's no VC rub by pushing the cone in and out.

The cones push in easily compared to foam surround woofers because the cloth is more compliant.

[Michael T]

1 hour ago, GD70 said:

The cones push in easily compared to foam surround woofers because the cloth is more compliant.

I figured as much, my bigger concern is that when I say bottom out, the VC actually hits the solid bottom of the magnet. This doesn't seem right.

[Michael T]

3 hours ago, genek said:

You should not use abrasive cleaners on printed logo plates. Abrasives are ok on the embossed, brown-lettered plates. Brasso makes a non-abrasive liquid cleaner called Gadget Care you can try (it's advertised as a cleaner for cellphone and other screens), but if there's any pitting on the surface, you're probably better off just ordering some repro badges.

There is no pitting, just some age.

[lARrybody]

The ancient Romans used olive oil to polish and clean brass. It actually works.

[stan461]

Michael T. & Roy C.,

Will look into each option.

Thanks to both of you for your help.

Always appreciated.

I'll post what I did in this thread and report back as to how the AR2AX's sound when restored.

 

 

[RoyC]

6 hours ago, Michael T said:

Another possible issue I found, the spider on both of the speakers seems to not be attached to the frame. It looks like it is attached to a masonite ring but the ring is not attached to the frame.

This is a common problem. Make sure you carefully check the spider ring as well...See attached photo. If you first re-glue the surround ring and the spider ring has the same problem, it will be more difficult to repair. The surfaces must be cleaned thoroughly. The oxide on the aluminum basket glue surface and old glue should be removed as much as possible.

Regarding the bottom-ing of the cone when pushed in, it is typical of these woofers.  As Glenn mentioned above, the spiders of these woofers were very compliant to begin with, and wear has only made them softer. It is very important to make sure the cabinet is sealed. The restorative force of the air in the cabinet is the basic principle upon which an acoustic suspension speaker works, and will compensate. Bass response will be impressive, though power handling may be less than that of a modern woofer.

Roy

[Michael T]

Thanks for the pic and advice, Roy. It is the rings around the spiders that have come loose. Unfortunately one of the woofers has the screen around the basket still in tact so ill have to get that off.

20 minutes ago, RoyC said:

Bass response will be impressive, though power handling will be less than that of a modern woofer

I have a Yamaha receiver from around 2008 or so. It's good quality and has a clean 90wpc output. Could I crank out some Depeche Mode with these babies if the mood struck me?

[RoyC]

12 minutes ago, Michael T said:

I have a Yamaha receiver from around 2008 or so. It's good quality and has a clean 90wpc output. Could I crank out some Depeche Mode with these babies if the mood struck me?

Probably...The power rating of the amp is less important than the room size/acoustics, and actual continuous volume level. AR tweeters usually go south before the woofers. I have seen more blown drivers due to transients (usually pulling rca plugs with the amp on, or turntable issues). Most recently I repaired a pair of 3a's used for a college "party". The engineering student owner was showing off his vintage system, which included a Pioneer SX-1250 receiver. He blew both tweeters, one midrange, and melted the plastic shafts of all (burned out) pots. The (12 inch) woofers survived.

Some 10 inch woofers like yours are having an adhesive issue where the voice coil attaches to the cone under the spider, but there is no way of predicting if or when it will occur. It is much less common than the surround and spider mounting ring problem.

Roy

[RoyC]

9 hours ago, Michael T said:

 I thought you were the leader of the geek squad, LOL. I only say this out of pure respect.

I had to think about that one, Michael. There are factions in Geek-dom, and I prefer to think of myself as a "general repair" geek. I don't like to see things become more complicated than they need to be for visitors who are just trying to get their speakers working again as a good representation of the model, without screwing them up in some critical way.

Using the Carli caps (and mylar/polyester caps in general) as an example, I still think they are an excellent and cost effective choice. I was only informing Stan that suitable caps could also be acquired from Parts Express if he wanted to place just one order. I have no proof that one is better or worse than the other despite the fact that Carli's have a bit more ESR than the Daytons. (As I mentioned above, the level controls probably negate any possible sonic differences anyway.) These days I often use Dayton caps only because I can easily get them at a wholesale price from nearby Larry/"Vintage AR". Frankly, some of the most impressive restorations I've heard, however, contain only a few dollars worth of electrolytic capacitors.

...so lots of choices, opinions, and discussion here, but they almost always lead to worthy AR repairs and restorations, regardless of the chosen path.

Roy

[GD70]

10 hours ago, Michael T said:

Thanks for the pic and advice, Roy. It is the rings around the spiders that have come loose. Unfortunately one of the woofers has the screen around the basket still in tact so ill have to get that off.

I have a Yamaha receiver from around 2008 or so. It's good quality and has a clean 90wpc output. Could I crank out some Depeche Mode with these babies if the mood struck me?

You can, just be careful with the volume knob!