TJet54

Good catch from the photo, I may need to edit my post. I do have the resistor in the mid range curcuit, closer to the terminals. I did not add the resistor to the tweeter. If my memory serves me correctly, you only add the resistor, if the tweeter is being replaced, which it has not. I do have those resistors. Although not in my photos, they will be included with the sale of the speakers. Thanks, all the best, Steve

For sale are my vintage Acoustic Research AR5 speakers, serial numbers 42961 & 42964, purchased in January 1976 from Stereo Discounters in Baltimore, MD. The speakers are fully functioning and in excellent plus condition with accompanying manuals and other AR literature. Factory rated @ 20-100 watts, the AR5’s really come to life and perform their best when paired with amplifiers in the higher end of this range for sure. Since downsizing my amps to low low watts only, I must let these speakers go. In 2019 the following work was done: The cross overs were thoughtfully updated with the knowledgeable advice from members of The Classic Speaker Pages Discussion Forums. The woofers were restored. The grill cloth was replaced. Capacitors – All replaced, BUT. The original Sprague compulytic 24uF mid-range capacitor remains, allowing you to choose the new caps or the vintage Spragues. Presently, the circuit is connected to the newer 12uf (x2 in parallel) Dayton Precision Audio Grade capacitors. The original, untested 4uf & 72uf AR caps will be included with the speakers, but as ?working?/parts only. Ceramic Mid & Hi Controls – Replaced with correct L-Pad attenuators. An attempt was made to clean and reuse the original AR 15.7-ohm rheostats, but I cautiously went with new. The old pots will be included but again as parts only. Tweeter & Mid-Range Speakers - Original, no issues. Woofers – New foam surrounds, new dust caps and testing were performed by Bill LeGall of Millersound, Lansdale, PA. Bill is arguably the best in the business for vintage speaker repair in the mid-Atlantic states. Grill cloth – Beautifully done using Wichelt’s 28 count, genuine 100% Irish linen in the color of Lambswool. This fabric is of the highest quality. The thread count & color is the closest you’ll come to matching the original AR grill cloth. The fabric is rightly fitted and drum tight, with a straight and true weave pattern. Brass AR5 Badges - Originals Cabinetry – The walnut veneer is in perfect original, un-refinished condition! Remarkably after 46 years, the cabinets are very close to pristine. You’d be hard pressed to find a scratch, chip, dent, nick, stain, or blemish anywhere! Throughout the decades the cabinets were properly maintained using Howard’s Restore-A-Finish. $750 cash, no returns. Because of the weight and fine condition, they’re being sold as local pick up only, SE of Hanover, PA. Feel free to bring your own amplifier and a familiar CD or two, for a no pressure, pre-sale audition. If you are serious about owning these but the distance between us is a stretch, I would consider meeting halfway +/-, within a reasonable radius. If there’s a rendezvous, two things must happen: One, a safe meeting place of my choice will be agreed upon, and two, I would like a reasonable PayPal amount to cover my driving expense. Thanks for looking!

In excellent condition, I just acquired these mid-century modern Telefunken RB 46 speakers. I believe these speakers were matched to the Telefunken Opus Studio 5650 MX tube AM/FM radio. Can anyone please tell me what the impendence and power rating is for these beauties? Thank you.

Never mind, I figured it out.

Hello, I need to refurbish my 5002's grills. How do you separate the two pieces of plastic that sandwiches the inner screen and grill cloth? Thanks, Steve

Do you have a pair of Dynaco A-25s with one very nice grill and one ugly or damaged? Here is one piece of genuine Dynaco speaker grill cloth in excellent vintage condition. It is from one of my A-35s, and has been in my smoke-free home(s) since the mid ‘70s. It is stain-free with no holes, no pulls, no weave gaps, just normal, typical color aging. The color is consistent from top to bottom except for a subtle lightening across the middle where the frame’s cross brace was. This lighter area seems to blend in with the surrounding color when the cloth is positioned back on my A-35s black frame. The top left and right photos involve camera shadows. The piece measures 12-1/4” x 21-1/4”. It will no longer wrap to fit a A-35, but will generously fit an A-25 or A-25XL. Pryor to cutting from the frame, low tack painter’s tape was applied to prevent fraying. This tape will easily release. The cloth will ship loosely rolled in a tube with no creases. $(snooze-ya-lose)00.01 - mailed to you If you wish, I can include my other stained grill cloth (no photo), at no cost. I doubt there is enough “clean” area on this second piece for an A-25. Perhaps it will be large enough for a Dynaco A-10. Thanks, Steve

I heard it through the grapevine the PE Lpad lugs are .120. Not 100% sure, but a tough size to find for quick connects. I guess i'll pre solder leads as needed since the lugs will be close to the wood. I'm planning on using insulated M&F quick connects to/from the capacitors to ease possible future cap changes. Decided to go small @ .110.

Are the lugs on the L-Pad for a .110, or a .187 female quick connect?

Is this photo correct, using the Parts Express L-Pad? If my tweeters have not been rebuilt, I do not add the 25 Ohm 10W resistor, correct? Thank you.

Yes, I did have them check (they used a Fluke hand held), and the 4 & 72 Industrials all measured +18% or greater. I'm sensing the 24uF Sprague Compulytic's must be important in maintaining the integrity of the restoration. The company that tested my caps specializes in control systems and power distribution. I'm not sure if they are into frequency/ESR stuff, but I'll ask. If i send my tweeters to chris1this1 who would replace the foam dampener behind the dome, build a replacement former and voice coil and resuspend and seal the assembly, I would need to add the resistor, correct? Other than the Parts Express 15W, 8 ohm L-pads/10W, 25 ohm resistor, what other options are there? Thanks

As a matter of fact, my 24uF orange caps are just like those. I took them to an industrial electrical service company here in town, and they measured 28.4 and 28.6. Since that is greater than 10%, I thought they weren't up to snuff. Go, or no go? Thanks

Hello, fairly new forum member here, and first time poster. First a little back story: I'm a retired H.S. shop teacher (not in electricity/electronics, but i can read a schematic and solder well). My hobbies are acoustic guitar repair, HO slot car racing and the endless search for the perfect hot sauce. My amplifier is a '74 Dynaco SCA-80Q I built in college, and has recently been modernized using the UpdateMyDynaco kits. This wonderful "new" amp powers my original A-35's to the fronts and A-25's to the rears. Kudos to Dan at UMDynaco. I don't remember my system sounding this good. Last spring, I came across a beautiful pair of 1976 AR-5's from the original owner. He worked at a Stereo Discounter's in Baltimore, and the preserved receipt (along with other literature) shows he paid $154 each with his employee discount. The serial numbers are 42961 & 42964. The cabinets are 99% perfect, the velcro attached grill cloths have never been off and the clear protective plastic is still on the brass badges, they're that nice. I bought them knowing they deserve some internal restoration, for sure. The woofers are back from Millersound with new surrounds. They look awesome, and Bill went above and beyond his stated service. The mid-range drivers and tweeters seem fine (by the 1.5v test), but it nice to know Chris1this1 is waiting, if the tweeters need attention. One pot in each cabinet (I can't remember if they were the mid or hi), shed a lot of what seemed like porcelain dust. Upon opening them i realized this white powder was solid at one time, and held the bottom half of the resistance coil in place. I also noticed these same two pots silver contacts were more pitted than the cleaner two. Just for fun, i tried this: 1) I carefully lifted the coil an put a small bead of clear silicone caulk in the well, and pressed the coil back in position. After the caulk cured, the coil seemed just as secure as the two good ones. 2) I pooled a little solder to the pitted areas of the contact plate, then sanded them smooth. Once i got over my accomplishment, i came to realize these two pots degraded for a reason, probably heat, and I shouldn't risk using them. So my first questions are these: Where do you think the degraded pots came from, the mid or the hi spot? Could I return the good pots to their original position and replace the bad ones with the Parts Express 15W, 8 ohm L-pads/10W, 25 ohm resistor, or should i just replace them all? (it's not about the $) My next question stems from an excerpt from the "Restoring the AR-3" file. "At maximum output, the parallel leg of an L-pad is disconnected from the wiper and can't provide the 16 ohm parallel resistance of the pot. The lack of parallel resistance can add load the hi-range driver when playing high levels at maximum clockwise shaft rotation; this is not so important with Ferrofluid-cooled hi-range as with the original AR driver." Can someone tell me what this means? If I don't play at high levels should I be concerned about this? And now, on to the 4uf, 24uF and 72uF capacitors..........I've read a lot about this on the forum, and my head is spinning. I keep coming back to this combination. Please offer your opinion: 4uf - use Dayton DMPC 4uF, 250v, 5%, PE#027-255. 24uF - use (2)Dayton DMPC 12uF, 250v, 5%, PE#027-430. 72uF - use (1)Dayton 22uF, 100V Electrolytic Non-Polarized PE#027-348 plus (1)Dayton 50uF, 100V Electrolytic Non-Polarized PE#027-354. (again, it's not about the $, I would go with 60/12uF DMPC's if justifiable). Please advise. My last question also comes from the "Restoring the AR-3" file. "If you install PP capacitors, you may wish to add a small amount of series resistance to compensate for their reduced ESR and maintain the authenticity of the AR crossover" [It then gives recommended values for the AR-3] Should i do this? If so, what values are appropriate for the 4uF, 24uF, 72uF AR-5 capacitors? Thank you so much for reading this, and hopefully taking some time to reply with comments or suggestions! Peace, Steve