Edward
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Posts posted by Edward
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Nice American hi-fi for sure.
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4 hours ago, Aadams said:
That thread has several opinions.
If these excellent examples ever come up for assessment against a normative 3a , originality will always require the least amount of explanation. To a knowledgeable observer the AR11 tweeter is an immediate sign of a non-standard configuration that should raise skepticism. Keeping the original internal configuration and putting the mod on the tweeter makes this more of an expedient tweak that is easier to explain. Without this thread as provenance, an objective, knowledgeable buyer of 3as would discount the value based on appearance alone and even more if the crossover is modified, unless, perhaps, the owner could show the page in the restoration guide on how to electronically reconfigure the crossover to take make AR11 tweeters compatible.
From a performance standpoint, the only tweeter that bridges the 5k gap between the classic mid and tweeter combo while maintaining the power response of the midrange unit, is the original tweeter. All subsequent tweeters are stronger on axis and do yield a different sound when the harmonics and overtones are strong in the 5k range. The only time this difference can be heard is using a rebuilt unit that has been tailored to crossover correctly at the 5k point AND if you are listening to source material that contains the information. Its kind of like torque in a Tesla, being there instantly in unmatched quantities when you need it but otherwise, unapparent to anyone when in normal use.
Adams
In the end, after my repairs have been completed, I will most certainly create a diagram showing what component are in the cabinets and why the particular caps and resisters were used. If next owner wants to rearrange the cap network they will at least know where they are starting from. This paperwork will be in a manila folder under home audio. My wife and I are quite organized that way.
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I will need to find an interested party for Sony TA-3120 and sell it before moving to more modern power unit. A warranty for the first several years cannot hurt.
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2 hours ago, DavidR said:
Have you considered Emotiva:
Also an option for sure.
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Thanks for that. just cannot see those old Elna caps in my Sony power amp living that much longer and remaining with acceptable tolerance. As previously mentioned in the forum under this thread, the QSC amps were suggested as an option. I really do not have all that much mula allotted for home audio. They certainly meet all my requirements. However, I am digging the preamp. I 'm looking for clean, simple, and reliable power source with power to spare so I'm remain lower on the dial. For a short period of time I owned pairs of both the AR-3 and JBL 100s (waffle grills) having the opportunity to A/B them. The ported JBLs were louder given a volume setting compared to the ARs. But the AR3 were much smoother (flat) to my ears with symphonic strings, jazz horns, and vocals. All my friends liked the JBLs better. I easily sold the JBLs for what I paid for them because I had ordered them from a catalogue sales company at a significantly discounted cost.
Yea the Sony TA-3120 seemed to power (stated 50 wpc rms) the AR-3 s just fine for a few decades. But those QSCs would also fit under the preamp much better.
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I would love twin tube amps, but @ 61 yo I'm looking for something small and little to no maintenance.
However they are great looking set.
Thanks, EE
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56 minutes ago, JKent said:
PS
I'm with you on the evils of streamed music (but don't let Frank catch wind of your comments on vinyl ?)Good advice from Lakecat. Maybe pull out a pot, open it and post photos. I'd still go with L-pads myself though.
Those Sony components are beauties from the heyday of Japanese electronics. If you want manuals etc. check here for the TA-2000 https://www.hifiengine.com/manual_library/sony/ta-2000.shtml and here for the 3121 https://www.hifiengine.com/manual_library/sony/ta-3120.shtml You'll have to "join" but it's free.
It's been noted here that the AR-3a likes a lot of power. Although the Sony's rating was "big watts" you may still be better off with more power--either a second 3121 or, many members here have praised the new cheap and powerful Crown or QSX power amps.
To all,
Yea lots of chatter about old classic amps that, however, contain tiring capacitors. I'm now clearly seeing that I do need to move to a more compatible amp for my AR3s. Interesting suggestions with good specs and not that costly. Does this mean that a newer amp will contain circuit boards with chips ??? -
43 minutes ago, JKent said:
PS
I'm with you on the evils of streamed music (but don't let Frank catch wind of your comments on vinyl ?)Good advice from Lakecat. Maybe pull out a pot, open it and post photos. I'd still go with L-pads myself though.
Those Sony components are beauties from the heyday of Japanese electronics. If you want manuals etc. check here for the TA-2000 https://www.hifiengine.com/manual_library/sony/ta-2000.shtml and here for the 3121 https://www.hifiengine.com/manual_library/sony/ta-3120.shtml You'll have to "join" but it's free.
It's been noted here that the AR-3a likes a lot of power. Although the Sony's rating was "big watts" you may still be better off with more power--either a second 3121 or, many members here have praised the new cheap and powerful Crown or QSX power amps.
I have A/b d vinyl vs quality CDs. I'm in favor of the wider frequency response of the compact discs and no background noise. You see I tend to drop things including the finest of vinyl records. And it is so easy to insert a disc vs pull out a record and place on turntable. And with a CD you can listed from beginning to end without flipping the plastic. I'm so glad to be rid of those cumbersome crates and the drying out of the cardboard slip covers, ...
The pots are in great condition, just need to have surfer reaction powder cleaned off and cleaned. Maybe Ill just keep the pots. Easier that way initially.
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37 minutes ago, RoyC said:
I agree with Kent (so often the voice of reason
). Going with the series 3.3uf/6uf arrangement allows you to more easily return to the original tweeter should the opportunity arise, which is well worth taking into consideration. There is no need to use the tweeter faceplate (foam or felt) treatment for the 3a.
I also agree with Jeff (lakecat), the later pots were much less prone to the typical debilitating corrosion.
Polarized capacitors in your electronics are not really in the same category as your non-polarized crossover filter capacitors...though, imo, too much confidence is placed in "vintage" amps, etc, which have not been completely restored.
Roy
And there are folks that will pay good money for these very Sony separates. They are in great shape, well sort of, they are old. Hmmmmmmm.
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20 minutes ago, JKent said:
This QSC amp will provide 425wpc into 4 ohms. It's new, warranteed and costs $350
https://www.sweetwater.com/store/detail/GX3--qsc-gx3-power-amplifier
The Crown XLS line has been praised by Tom Tyson (of Restoring the AR-3a fame) and others. The 1002 delivers 350wpc into 4 ohms and costs $340. https://www.sweetwater.com/store/detail/XLS1002--crown-xls-1002-power-amplifier
Just a thought for down the road. 3a's like 100wpc or more. More importantly, they are 4 ohm speakers and your Sony is only rated for 8 to 16 ohm loads. I know that combo has worked for you for decades but I'd say "danger Will Robinson".
btw, found an interesting writeup on the TA-3120 here https://forums.stevehoffman.tv/threads/from-the-vintage-solid-state-vault-the-sony-ta-3120a.329715/
Kent
I have been coming across references to QSC amps as of late but was not familiar with them. I am not stuck on the Sony separates as I am with my AR-3s.
Seems like I may need to look into this ohm aspect of the Sony amp.
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21 minutes ago, JKent said:
Edward,
I admit I've never actually seen an AR-11 tweeter. Is the thin wide foam you refer to a diffraction ring on the face of the tweeter? If so, they can be replaced with these: https://www.madisoundspeakerstore.com/acoustic-damping/dampers-felt-defraction-ring-for-tweeters/ They are $2 each. Ebay seller "Vintage AR" sells the exact same rings for $15/pair.
There are 2 ways to go with the tweeter cap. The simple way (that Roy described) is to chuck the 6uF and put in 2uF. What you described, i.e. replacing the old 6uF with a new film 6uF on the board and then adding a 3uF in series with the negative terminal is another way to go and in a sense more "authentic", since the factory would have done it that way. But unless you plan to find original 3a tweeters and have them rebuilt to replace the 11 tweeters in there, why go to that trouble? I think we all agree that Roy is the 3a guru and if he said just replace the 6uF with a 2uF you can take that to the bank.
It is wise to have your '70s era components checked periodically and it sounds like your tech, like mine, believes "if it ain't broke don't fix it". A total re-cap is a really big job.
Kent
Foam: I believe I read in the AR3 restoration manual that it is to reduce unwanted dispersion. For a few buck I'll order them. Thanks for the options. Otherwise I may fabricate them matching thinness.
Caps: Had I diagrammed these alternative I would have conceptualized these options earlier. I'm going with the Roy suggestion: replace the old 6uF and put in 2uF. (vs replacing the old 6uF with a new film 6uF on the board, then adding a 3uF in series with the negative terminal).
You all have been very patient with me. Closest to original sound driven by logic is my priority , over the "authentic" option I was inadvertently stating. Future owners will understand. Can't wait to run some Stravinsky and Miles Davis through them once completed.
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57 minutes ago, RoyC said:
As official spokesman for the " "Help Restoring My AR-3a group", the L-pads are fine with the 25 ohm parallel ohm resistor on the mid, and a 2uf capacitor on your AR-11 tweeters.
Roy
Thanks RoyC,
25 ohm parallel ohm resistor on the mid, and a 2uf capacitor on the AR-11 tweeters -- duly noted.
Added to list. The AR-3a restoration manual is truly a classic.
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55 minutes ago, lARrybody said:
Not even FrankenAR. Now replace your woofer with Radio Shack woofers and your tweeters with Peerless soft domes then maybe. You want to install new L-pads because the original aetna-pollak pots are past their life expectancy. Your 20001-1 tweeters are ferro -fluid and will handle more power. Just do the crossover mods. If you must have the original 3/4 in. hard dome tweeters they can be found and rebuilt by either RoyC or Chris1 to like new condition.
Great news !!!
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2 minutes ago, lakecat said:
Don't be so quick to throw away those pots. There is a double swipe in those later models...and have found them to be in pretty good shape. You have some of the last built speakers with those serial numbers.
lakecat,
After replacing pots for lpads I will no longer have any use for the four pots removed. You are correct there does seem to be two layers of metal swipes, with the top one extended out to contact the coils. If there is interest in them, I would give first refusal options to the individuals who have responded to my forum posts, and the order they responded. I'm not $$ grubbing but it would be nice to receive something to offset the costs for repairs discussed and postage. Just some white powder on metal surfaces (sulfur?).
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24 minutes ago, JKent said:
So there you have it. Forget the 6uF caps and install 2uF in their place. Solen and Dayton 2.0uF caps are available from PE. They are so cheap I'd go for the 1% tolerance but even the 5% are probably spot on
Thanks for the link to PE: 027-214, Dayton Audio, 2.0 µF, 1%, 250V.
I still need to summarize this info, so my PE order includes all the changes/additions (resistor) that have been discussed today.
You guys ROCK !!! Thanks for taking the time to guide me back to my previous world of a flat audio response.
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4 minutes ago, Aadams said:
Lpads, properly setup, are a well accepted tweak and way better than the best used 40 year old pots. The tweeter is not a problem either, cap or no cap, as long as you don't mod the internals to compensate. The new 6 mf cap gets placed on the board but the additional 3.3 is placed in line with the negative terminal wire and connected to the the tweeter so the mod comes out easily if you ever install rebuilt original tweeters. You would have to know what to listen for to ever the difference.
PS Don't forget to ask about that lpad resistor.
Aadams
That is what I'm gathering -- more about keeping the vintage usable in the 21th century -- so no unnecessary mods to internals.
Pots out and replace with lpads. And I guess now I'm conceptualizing the changes to account for my replacement tweeters; change cap as prev discussed (6mf on board), and insert the 3.3 resistor in series with negative terminal. I was a little slow picturing this arrangement.
Other caps: The interesting thing is that the caps in my 1970s Sony separates are old as well. Our local Classic Audio Repair shop scoped my amp and found the original Elna caps were generally still OK. He was a bit surprised but stated that Sony used quality parts in their assembly of this audio series. However, two caps on the power supply board of preamp were faulty and were replaced. They provide old parts in a bag upon pickup. The set sounds great to my ears, albeit with my back-up two-way ported speakers. My point is that after the caps on the AR board, I will still have aging Elna caps in my electronics.
Music source: My source is a CD player. Over the course of about one year I traded in my collection of rock/pop/jazz/classical vinyl at ~6 wooden crates. The local record shops were relativity generous when trading in for in-store credit. I love the wide frequency range of compact discs as opposed to the compressed vinyl format and no pops or clicks !!! I do not stream music, too compressed for me.
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Aadams,
Not installed. Appears to have been a quick repair with, at the time, contemporary tweeters.
To all,
Any telling if myAR-3a's, with the later version tweeters and swap of pots for lpads, will be viewed by the "Help Restoring My AR-3a" group as "Frankenar's" (Frankenstein + AR's)? Or is vintage AR tweaking typical/accepted as necessary modifications (caps, lpads)? The difference is that my pair will also contain relatively newer version of tweeters (by 2-3 years).
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40 minutes ago, Aadams said:
"3uf cap in series with the original 6uf cap"
"So it appears that the tweets were replaced with an upgraded model"
I wouldn't say upgraded just more robust.
Edward
Don't forget to ask about the tweeter lpad resistor if you are keeping these tweeters.
Aadams and others,
On that same note. So I would add a new 3uF cap in series with a NEW 6uf cap? Or do I add a new 3uf cap in series with the ORIGINAL cap. that is presumably in need of replacement?
Also a follow up to RoyC's comment rearguarding replacement tweeters: following the figures in Champagne et al. 2007, the originals were most likely 200013-1s (for AR-3a, AR-LST) as seen in Fig. A.20, (dates 1974-1975; pg. 31), with 1200011-1s (for AR-10 π , AR-1) installed as replacements (Fig. A.24, dates 1977-1978; pg. 32; 1200011-1). It is all making sense to me now. The speakers were purchased by original owner on 19 Dec 1975 (on receipt) and I must have bought them sometime in 78 with blown tweeters. Under warranty I had the tweeters repaired free of charge upon purchasing them. The replacement components had that same thin wide foam with a circle painted on it prior to it dissolving into powder.
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Roy,
Holy mackerel you are correct. When I listened to them at the home of the seller I tested them toughly and discovered that the tweeters were blown. However, since the original sales receipt was available, and they were still under warranty, I took them down to have repaired by factory authorized service shop. I only paid $200 (which I knew was a deal) for the pair in about 1976-ish. So it appears that the tweets were replaced with an upgraded model, with further required modifications not made to correct responce. I need to replace high caps with "3.3 uf cap in series with their negative terminal" (RoyC). I was looking at the pictures in the "Restoration Guide" and the details provided for the drivers and was thinking that the tweeters info need to be adjusted to include the 1975 date of my speakers, but the tweeters in my speakers are not the original models. That clears that up -- restoration guide correct. Man-oh-man you guys are good.
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1 hour ago, JKent said:
I see you decided to use a film cap for the 6uF. The Solen is a fine choice, you could also use this Dayton
https://www.parts-express.com/dayton-audio-dmpc-62-62uf-250v-polypropylene-capacitor--027-427
If Solens not in stock when checking stock I'll also consider the Daytons.
Thanks Kent
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1 hour ago, JKent said:
I see you decided to use a film cap for the 6uF. The Solen is a fine choice, you could also use this Dayton
https://www.parts-express.com/dayton-audio-dmpc-62-62uf-250v-polypropylene-capacitor--027-427
I'm going with the film caps based on what I have read in previous posts on the AR Restoration Forum, or maybe in the detailed in the, Champagne, Kantor, Luong, O’Hanlon, Thiel, Tyson (2007) Restoring the AR-3a Guide.
What artists do you play through your AR-3a s.
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Adams,
AR-3a was written on original receipt with a sale date of 19 Dec 1975. The AR manual provided also states AR-3a. Cabinet serial #s ( next to knobs on Xover board) are 101822, 101829 for "AR-3a".
Once the Xover is restored with previously discussed caps and the woofer foam surrounds replaced, I will audition the sound, prior to having tweeters rebuilt. However, I do plan on having tweeters rebuilt, based on your recommendation, prior to sitting back and enjoying Frank Zappa, Herbie Hancock, Beatles, Dave Brubeck, Beck, Stanley Clarke, Switched-On-Back, Hendrix, Miles Davis, etc. ...
At one time I had purchased a pair of JBL 100s (with waffle grills) and did not feel they could even compare to the AR3a's. The flat response and clean bass of these magnificent AR3a speakers provides a unique settling listening experience. Looking forward to bringing them back to former glory.
Pictures below - the wide thin round foam previously surrounding the tweeter flaked off.
Thanks for your guidance, EE
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I appreciate your knowledgeable input. I'm looking at my Xover and there is an AR sticker for AR-3a (#101822, 101829). I'm no longer unsure of what I own. Thanks for confirming my parts list. I'll check PartsExpress for the two 25 ohm 10 watt resistors that I will need. I'll also check back posts for recommended lpads.
a) OK foam surrounds it is, b) to my grocery list I'll add (4) lpads, (2) 25 ohm 10 watt resistor for mid-range lpad connection, & (6) 50mf caps (instead of one 150 for each woofer).
I was able to photograph my Xover because it has been removed and on my desk. I hope the pic uploads smoothly.
I purchased my AR3 pair from my high school girl friends father for $200 back in about 1976. I knew it was a steal and a dream come true back then. I was the odd man out because all my friends were buying R&R Cerwin Vegas for Led Zeppelin. Her dad was the original owner and provided me with the original receipts. I have hauled them around; college, apts., move from Chicago to So. CA, more apts, to my current home in San Diego. The cabinets are in great shape. I have thrown out my back on several moves - I would not anyone else carry them, not that anyone was eager to do so (!). They are usually hooked up to my Sony separates; TA-2000 pre amp & TA-3120 power amp (50 wpc, but this number is very conservative). This has been my system for over 4 decades. I love it.
I'll post pics of my drivers after I remove them again.
Your guidance is extremely helpful and appreciated. Ed
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To all AR Guru's,
For my AR3 woofers it is time to replace the foam surrounds once again, is there a cloth surround alternative in lieu of the typical foam that seems to be the standard material. It seems there must be a better alternative that would last longer and be compatible with the designed sonic characteristics.
Edward
Help Restoring My AR-3a's
in Acoustic Research
Posted · Edited by Edward
grammer/spelling
The future of my soon-to-be refurbished AR3s is ;
By choice, my only source of music now is a cd player. Two years ago I moved from a Duel 1229 TT (sitting in my garage) to an older Pioneer PDM 550CD player; including the collections of each of the formats.
Like many of you, I test drove a wide variety of separates over the last several decades. But back in 1978 I bonded with the sound produced by the magnificent AR3a's, for a wide of genres, as long as it was clean power.
Soon I will diagram my cap. replacements with resistor for the newer ver tweeters and post on this thread. And since the metal surfaces are not corroded I will properly clean and treat metal to revive original Pots.