Heatkit AR-3a's

[Darrell Peart]

I picked up two pairs (4 speakers) of Heathkit AS-103a's this weekend. From what I understand they are essentially original equipment AR-3a’s with Heathkit cabinets. Is this true?

The woofers all need re-foaming and at this point I can only get sound out of one cabinet. The cabinets all look in relatively good shape - they do not look abused. I got them from the original owner (who assembled them). They have been stored in his basement for over 10 years.

Are these worth fixing? I am more interested in the sound quality than resale value or collectability.

[JKent]

Are these worth fixing?

Absolutely! Congrats on the great finds! Let this be your "bible":

http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_schematicss/restoring_the_ar-3a/restoring_the_ar-3a_full_pd.pdf

Have fun with the restoration!

Kent

[michiganpat]

no, and as a public service, I'll get them out of your hair for no cost....

[Darrell Peart]

Absolutely! Congrats on the great finds! Let this be your "bible":

http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_schematicss/restoring_the_ar-3a/restoring_the_ar-3a_full_pd.pdf

Have fun with the restoration!

Kent

Thanks - Do you know if these guys in fact have all genuine AR components?

[Darrell Peart]

no, and as a public service, I'll get them out of your hair for no cost....

Thats odd - I have already had a few similar offers from friends.

[dynaco_dan]

Thats odd - I have already had a few similar offers from friends.

Hi there

Heathkit advised early on that the speaker owners should add glue to all of the inside cabinet joints.

This would be a good idea here as well.

[Darrell Peart]

Hi there

Heathkit advised early on that the speaker owners should add glue to all of the inside cabinet joints.

This would be a good idea here as well.

Yes - good point. I intend to run a bead of hot-melt glue around all the inside joints and seams. Without opening them up - it looks the guy who assembled them followed that advice as well - with the grills off I can see generous amounts of glue around the perimeter of the face piece where it meets the sides and tops and bottoms.

[JKent]

I believe these cabinets came pre-assembled but I don't know if they had the same internal bracing as the AR product--if not, consider adding bracing. Maybe someone with 1st-hand experience with these could address that. The drivers ARE all original AR. Don't know about the capacitors but those should be replaced anyway. I know the Heathkit version of the AR=2 did NOT use Aetna-Pollack pots so that may be true of your speakers too. But if your speakers are not working, maybe you should hope you do have A-P or similarly crappy pots. Although others may disagree, I've become a fan of Roy & John's L-pad mod described in the restoration booklet.

Not sure hot-melt is the best choice. Seems to me it could dry and shrink. I'd be inclined to use carpenter's glue or hide glue unless the original owner already did the extra glue thing.

Kent

[Carlspeak]

I have a digital copy of the Heathkit AS-103 owner's manual. PM me with your email address and I'll send it along.

[dynaco_dan]

Yes - good point. I intend to run a bead of hot-melt glue around all the inside joints and seams. Without opening them up - it looks the guy who assembled them followed that advice as well - with the grills off I can see generous amounts of glue around the perimeter of the face piece where it meets the sides and tops and bottoms.

Hi there

The glue was to be applied to all the inside seams, NOT the outside.

Regular wood glue, NOT hot glue.

For the AS-2 speaker they used 3 sides of marine plywood and one side of regular.

They did not use the same strong locking mitre joints that AR cabinets had.

Of course gluing these was to be done prior to assembling.

You will need to remove the fiberglass and vacuum the cabinets out first to do it right.

There is two separate models, AS-103 and AS-103A, slightly different.

[Darrell Peart]

I believe these cabinets came pre-assembled but I don't know if they had the same internal bracing as the AR product--if not, consider adding bracing. Maybe someone with 1st-hand experience with these could address that. The drivers ARE all original AR. Don't know about the capacitors but those should be replaced anyway. I know the Heathkit version of the AR=2 did NOT use Aetna-Pollack pots so that may be true of your speakers too. But if your speakers are not working, maybe you should hope you do have A-P or similarly crappy pots. Although others may disagree, I've become a fan of Roy & John's L-pad mod described in the restoration booklet.

Not sure hot-melt is the best choice. Seems to me it could dry and shrink. I'd be inclined to use carpenter's glue or hide glue unless the original owner already did the extra glue thing.

Kent

I am feeling really DUMB!

I had noticed the fuse in the back early on - but for some reason I did not make the connection when 3 of the cabinets did not give any sound. Upon inspection two cabinets do not have fuses and one looks blown. My local radio shack did not have replacements. I will either find them somewhere else tomorrow or change out the good fuse to the other cabinets.

I will open up my (real) Ar-3a's and compare the internal bracing with that of the Heathkits.

There is some new hot-melt glue that ( so far) does not show any signs of cracking but I will play it safe and use yellow (carpenter’s) glue.

[Darrell Peart]

There is two separate models, AS-103 and AS-103A, slightly different.

Thanks for the info - would there be any advantage to having either model - Mine are As-103a with a 1977 date on them.

[JKent]

I am feeling really DUMB!

Join the club!

Actually, that's very good news. The fuses did what they were supposed to do.

Although some would disagree, you don't "need" the fuses IF you are using a modern amp with built-in protection for the speakers. You can just bypass the fuses to check the speakers. Just don't crank 'em up because you have not checked the speaker surrounds yet. I don't know if those have cloth or foam.

If you do want to fuse the speakers, Vern had a good source for the correct fuses. Maybe he'll chime in here. Also take up Carl's offer of a scanned manual. Info on fuses and glue should be in there.

IMPORTANT: Remember these are 4 ohm speakers, You'll have to use an amp that is capable of driving 4 ohm loads.

Kent

[michiganpat]

Thanks for the info - would there be any advantage to having either model - Mine are As-103a with a 1977 date on them.

interesting on the year...would these have leftover 3a drivers in them, or AR11 drivers, given the '77 date stamp?

[Darrell Peart]

I have a digital copy of the Heathkit AS-103 owner's manual. PM me with your email address and I'll send it along.

Thanks Carl !

[Darrell Peart]

Join the club!

Actually, that's very good news. The fuses did what they were supposed to do.

Although some would disagree, you don't "need" the fuses IF you are using a modern amp with built-in protection for the speakers. You can just bypass the fuses to check the speakers. Just don't crank 'em up because you have not checked the speaker surrounds yet. I don't know if those have cloth or foam.

If you do want to fuse the speakers, Vern had a good source for the correct fuses. Maybe he'll chime in here. Also take up Carl's offer of a scanned manual. Info on fuses and glue should be in there.

IMPORTANT: Remember these are 4 ohm speakers, You'll have to use an amp that is capable of driving 4 ohm loads.

Kent

I passed the one good fuse around. All the woofers at least make noise - and some of the tweeters and mids woke up as well. It is likely level controls are the problem with some (I hope).

I have a few good amps/recievers to drive these (I also have an original pair of AR-3a's and a pair of AR-10pi's) - Marantz 2285b - Sansui 9090 - Phase Linear 400 series 2.

[Darrell Peart]

interesting on the year...would these have leftover 3a drivers in them, or AR11 drivers, given the '77 date stamp?

I may have miunderstood the '77 date stamp, it appears that may have been a repair tag.

I have attached some images I took this morning - the last one (showing the lock miter) may be difficult to understand.

[JKent]

Nice! I like the binding posts (color coded to boot) and built-in fuse. As you know, these details differ from the AR version. The cabinets are different but nice and they should clean up nicely. Could not make out the lock miter but will take your word for it. Cabinets seem to be of high quality. Do you have all 4 grilles?The baffle is recessed more than the original 3a and some would take issue with that design. Wonder if Pete's BSC would be useful with these.

Those appear to be A-P pots. Apparently you are experienced with the 3a, so you know your options: Clean them up, replace with L-pads & resistors or replace with Ohmites. And of course you'll need new surrounds (I like M_Sound kits. You can probably get a discount on a double kit).

Keep us posted.

Kent

[Darrell Peart]

Nice! I like the binding posts (color coded to boot) and built-in fuse. As you know, these details differ from the AR version. The cabinets are different but nice and they should clean up nicely. Could not make out the lock miter but will take your word for it. Cabinets seem to be of high quality. Do you have all 4 grilles?The baffle is recessed more than the original 3a and some would take issue with that design. Wonder if Pete's BSC would be useful with these.

Those appear to be A-P pots. Apparently you are experienced with the 3a, so you know your options: Clean them up, replace with L-pads & resistors or replace with Ohmites. And of course you'll need new surrounds (I like M_Sound kits. You can probably get a discount on a double kit).

Keep us posted.

Kent

I wish I had time to work on these myself - but I am way too busy with my furniture making business. I am dropping them off with Doug Macdoor today. He was the one who figured out the problems with my (original) Ar-3a's. Doug is very knowledgeable and detail oriented.

I will clean up the cabinets myself and make two new grills (2 were missing) and install new grill cloth. Hopefully they all can be put back in working order – if not maybe get one good pair. I also have an orphaned 3a I bought for parts when restoring my original 3a’s- might come in handy here.

Not sure what I am going to do with 3 sets of 3a’s but I just could not pass these up. The thought occurred to me to set them up in my home theater room with my Yamaha surround sound receiver, but I am not sure if 4-ohms is going to be an issue there. I would love to hear my 5:1 SACD’s through these.

[Darrell Peart]

Nice! I like the binding posts (color coded to boot) and built-in fuse. As you know, these details differ from the AR version. The cabinets are different but nice and they should clean up nicely. Could not make out the lock miter but will take your word for it. Cabinets seem to be of high quality. Do you have all 4 grilles?The baffle is recessed more than the original 3a and some would take issue with that design. Wonder if Pete's BSC would be useful with these.

Those appear to be A-P pots. Apparently you are experienced with the 3a, so you know your options: Clean them up, replace with L-pads & resistors or replace with Ohmites. And of course you'll need new surrounds (I like M_Sound kits. You can probably get a discount on a double kit).

Keep us posted.

Kent

I wish I had time to work on these myself - but I am way too busy with my furniture making business. I am dropping them off with Doug Macdoor today. He was the one who figured out the problems with my (original) Ar-3a's. Doug is very knowledgeable and detail oriented.

I will clean up the cabinets myself and make two new grills (2 were missing) and install new grill cloth. Hopefully they all can be put back in working order – if not maybe get one good pair. I also have an orphaned 3a I bought for parts when restoring my original 3a’s- might come in handy here.

Not sure what I am going to do with 3 sets of 3a’s but I just could not pass these up. The thought occurred to me to set them up in my home theater room with my Yamaha surround sound receiver, but I am not sure if 4-ohms is going to be an issue there. I would love to hear my 5:1 SACD’s through these.

[dynaco_dan]

I may have miunderstood the '77 date stamp, it appears that may have been a repair tag.

I have attached some images I took this morning - the last one (showing the lock miter) may be difficult to understand.

Hi there

If I remember correctly, Heathkit used a standard 3 amp fast blow fuse in that fuseholder.

Without someone else has more technical advice, I would suggest downsizing to perhaps a 2 1/2 or even 2 amp glass fast blow fuse for the old drivers.

Dynaco A-50's used a 1 1/2 amp fast blow fuse and could handle a substantial amount of power, yes I know, 4 ohms versus 8 ohms.

I have been using a 1 amp fast blow fuse in a open style fuseholder for decades in most all of my speakers.

Yes, I have blown some fuses when over doing it and I have always kept spares on hand, at about 25 cents each.

AR recommended Bussmann Fusetron FNM-1 1/4 amp dual element slow blow fuses, also equal to Littlefuse FLM 1 1/4.

These were recommended using with an open style fuseholder.

The fuses and fuseholders have escalated to very high prices, like everything else.

Sometimes available at surplus prices, if you find them without S&H and postage charges that are out of sight for perhaps 5 or 10.

Heathkit used an o-ring under the fuse cap to seal the fuseholder.

What I see in the cabinets rear photo appears to be just a 45 degree mitre only, same as the AS-2 series.

Heath bought their cabinets from a different supplier than AR.

I still remember drooling over the AS-103A's at our local Heathkit store, I bought an assembly manual only.

The AS-103A has the later crossover.

Update 20110712 10:00 PM

Heathkit never had a sale price for their regular products.

I do not remember what their retail price was.

You could buy all of the parts at a store, including drivers, at the book price, plus a percentage, plus taxes.

The drivers were sold only on an exchange basis, AR's way of protecting their product line.

10:30 PM I went back to the cabinet photo again and I believe that I was wrong, it does appear to be a lock mitre joint, or I'm tired.

[Darrell Peart]

Hi there

If I remember correctly, Heathkit used a standard 3 amp fast blow fuse in that fuseholder.

Without someone else has more technical advice, I would suggest downsizing to perhaps a 2 1/2 or even 2 amp glass fast blow fuse for the old drivers.

Dynaco A-50's used a 1 1/2 amp fast blow fuse and could handle a substantial amount of power, yes I know, 4 ohms versus 8 ohms.

I have been using a 1 amp fast blow fuse in a open style fuseholder for decades in most all of my speakers.

Yes, I have blown some fuses when over doing it and I have always kept spares on hand, at about 25 cents each.

AR recommended Bussmann Fusetron FNM-1 1/4 amp dual element slow blow fuses, also equal to Littlefuse FLM 1 1/4.

These were recommended using with an open style fuseholder.

The fuses and fuseholders have escalated to very high prices, like everything else.

Sometimes available at surplus prices, if you find them without S&H and postage charges that are out of sight for perhaps 5 or 10.

Heathkit used an o-ring under the fuse cap to seal the fuseholder.

What I see in the cabinets rear photo appears to be just a 45 degree mitre only, same as the AS-2 series.

Heath bought their cabinets from a different supplier than AR.

I still remember drooling over the AS-103A's at our local Heathkit store, I bought an assembly manual only.

The AS-103A has the later crossover.

Update 20110712 10:00 PM

Heathkit never had a sale price for their regular products.

I do not remember what their retail price was.

You could buy all of the parts at a store, including drivers, at the book price, plus a percentage, plus taxes.

The drivers were sold only on an exchange basis, AR's way of protecting their product line.

10:30 PM I went back to the cabinet photo again and I believe that I was wrong, it does appear to be a lock mitre joint, or I'm tired.

It is very difficult to pick out the lock mitre in the photo - I have attached a sided by side comparison with one image marking out the joint.

Good advice on the fuses - thanks.

Could I add a fuse to any speaker by simply adding a fuseholder in the speaker line? If so, would I add it to the positive or negative side (or does it matter)

The reason I ask is probably worth another posting - I recently acquired a Phase Linear 400 series 2 amp and hooked it up to my AR-10pi's - with the extra wattage (210 wpc) my 10pi's never sounded so good. The improvement is quite dramatic in fact! I have heard that the PL amps can be unstable and when they go - they can take a set of speakers with them. My 10pi's are my #1 prized speakers and do not want to damage them.

[JKent]

Could I add a fuse to any speaker by simply adding a fuseholder in the speaker line? If so, would I add it to the positive or negative side (or does it matter)

this is in the Library under "additional AR documents":

http://www.classicsp...#previous-photo

[Darrell Peart]

this is in the Library under "additional AR documents":

http://www.classicsp...#previous-photo

Thanks Kent - exactly the info I needed!

[dynaco_dan]

It is very difficult to pick out the lock mitre in the photo - I have attached a sided by side comparison with one image marking out the joint.

Good advice on the fuses - thanks.

Could I add a fuse to any speaker by simply adding a fuseholder in the speaker line? If so, would I add it to the positive or negative side (or does it matter)

The reason I ask is probably worth another posting - I recently acquired a Phase Linear 400 series 2 amp and hooked it up to my AR-10pi's - with the extra wattage (210 wpc) my 10pi's never sounded so good. The improvement is quite dramatic in fact! I have heard that the PL amps can be unstable and when they go - they can take a set of speakers with them. My 10pi's are my #1 prized speakers and do not want to damage them.

Hi there

Your cabinets do have the 45 degree lock mitre, a much stronger glued joint than just a 45 degree mitre and the same as AR's.

Likely you may only need to glue the inner front baffle and side joint, if at all.

This may mean that the AS-103 series used AR supplied or at least spec's cabinet construction.

Just use the existing chassis fuseholder with a fast blow glass fuse and think about downsizing the amperage.

There is absolutely no reason to add an additional in-line fuse, unless you bi-amp them, that's another story.

I do not have the schematic in front of me to see if the entire speaker system or just the mid/tweeter is fused.

If it is the entire speaker, then only that one glass fuse will work.

As the world turns for today.