AB3CX MIke

https://www.facebook.com/marketplace/item/2805160063101433

https://www.facebook.com/marketplace/item/2426173944346399

3 blocks

Cooperstown. Some call it the Leatherstocking region after James Fenimore Cooper.

Thanks for the info, that works!

I have an opportunity to acquire a pair of KHorns but would need to find a new owner for these. The story is that an older couple ownd these since 1978, passed them to their son in 2017 who passed them to a friend who sold them to me. I recapped the AA crossovers with Daytons, but have not done anything else. They are painted a light brown, and are in decent shape, very presentable as is, but one badge is missing. Sound is great, all original drivers. $1200 takes them. My pictures are too large to upload so contact me and I'll send a set to you via PM

It seems like 8 months ago youy could buy Chorus II for 750-800, those days are over. Why not just get a nice used pair of Cornwalls at this point?

https://watertown.craigslist.org/ele/d/lehigh-valley-beautiful-vintage-1970s/7150409549.html $3500 is asking, look nice

https://syracuse.craigslist.org/ele/d/liverpool-klipsch-forte-speakers/7182950753.html Forte I's reasonable price

https://www.facebook.com/marketplace/item/2739293369726799/

https://www.facebook.com/marketplace/item/347548999749939/ $3500, look very nice.

One last question...The crossover thread for AA's suggests disconnecting the Zener diodes. Please explain why and what was their function in the first place which is not needed now?

Here is the result of the capacitor check: ( all caps removed from circuit before checking.) the two high value caps were Sprague 14 ufd 150 VDC. One measures 15.2 ufd with 0 ESR, the other 18 ufd with 0 ESR All four of the 2 mfd caps were CDE rated 200 VDC. They were all pretty much spot on and all four had 0 ESR also on the meter. So none of them were leaky. I decided that since 13 mfd is the correct value per the posted schematic for the crossover high value cap, to put new matched ones in for those two. To my surprise, I did decide the audio improved, notably. So I replaced the rest. My music test for speaker quality is Mozart's Clarinet Concerto in A Major. Having worked in antique radios for years, I had always thought that a cap was a cap, if it was good and on target for value. So my experience set me up to not expect an improvement in sound. I would have to say that the clarinet solos sounded crisper, not as diffuse and the orchestra just better. Maybe having gone to all the trouble we become biased to hear improvement, hard to say, this is not an A/B test clearly. In any case, certainly recapping does not in any way seem to degrade the sound, so I'm now a convert and will recap in future. Some of you experts please look at the pic of the caps I removed and let me know if these were originals, or themselves replacements?? IMHO the soldering looked factory and undisturbed and have seen alot of radio chassis. As far as the discussions about various brands of caps, it should be noted that there are only so many cap factories in the world, so the small volume higher end caps are probably made in someone's larger plant, like many craft beers.

I bought a walnut pair 5 months ago for $700 from AudioClassics, and sold them 3 months later for $750 in order to trade up.

I thank all for the input. Over the next few days I am going to do an "experiment". I am going to use a component tester to check my new caps for value and ESR before installing them. I'll swap in the new for old and check the values on the old ones. Of course the subjective or sound test is the one that counts, but I'm curious how the old caps may or may not have held up. Component testers are now very easily purchased and can quickly analyze individual caps or circuits, of course these are static and not dynamic tests under load, but they convey some idea of component quality.

Price was more than reasonable

After owning some Forte IIs, loving them, and then selling them to upgrade to Cornwall 3's, I have finally succumbed to a local sale for a pair of late 70's LaScalas (3N610 and 3N612). These have AA crossovers. All the drivers are good and with only a new Mid-Fi Yamaha solid state driving them, they sound fabulous. The LaScalas are at a vacation house, in a high ceilinged open space in a log cabing type structure. The Cornwalls are on a McIntosh system at home, but in a room a bit small for the speakers to separate widely. The LaScalas sound grand in the larger space. I've read up on some of the crossover updating threads, and felt initially that the caps should be replaced. The new caps are on order, but my anxiety is that the new caps might change the sound in a negative way, since things sound pretty good now. I could always save the old caps, or at least test them on a component analyzer before soldering in the new ones. Sometimes leaving well enough alone is not a bad thing. Thoughts??

Where are you located?

This is the schematic to the amp pictured above. Easily driven by a CD player alone. The cool part of the adaptation is that a Scott 510 has two rectifier tubes. The 25Z5 was pulled, the filament voltage rectified with a diode bridge to get one bias voltage. That is in the little octal plug on the left side. The other bias voltage was generated with a very small transformer giving 150V. Most builders would more easily use a typical antique radio transformer to generate the plate B+, and the required filament voltage. These big old battleship vintage radios which used two chassis have lots of room under the hoods, all the iron plus nice output transformers. I have my eye on a Facebook Marketplace Capehart Panamuse M-FM which would yield the needed parts for my twin, but is too expensive at the moment....

I had so much fun with the Little Sweetie, I built this push pull 6L6 a few days later. The chassis was originally the amp/power supply from a Scott 510. Construction was easy. This one really is a step up, but to get an identical looking twin I need to find another Scott 510 to cannibalize.

Hi Jeff, I think I may have bought this output transformer years ago on eBay thinking of a future project. May have paid $15 plus shipping then. Literally every part for this was on hand in the shop. So I wired it up last night and tested it today. Basically I ran the output of the CD player right into the phono input jack, and fed the output 8 ohm tap to an old Large Advent speaker. Honestly it sounds great I initially had some hum, which was eliminated when I made the connection at point B on the schematic. Originally I did not get why it was designed that way, but following the instructions can't hurt!! I used electrolytics 22 ufd/450 volts because that's what I had on hand, which does not seem to hurt it at all. As far as volume, it's plenty loud at about 25% rotation of the volume control. I happened to try a 6L6GA I had on a shelf, I think it sounds better than the 6Y6. I am going to play around with it a little more, I could have done a neater job under the chassis. I'd recommend this to anyone to try...

BTW, to see pictures of the Forte II speakers, follow this link: https://oneonta.craigslist.org/ele/d/cooperstown-klipsch-forte-ii-speakers/7068315621.html

It's a real museum. When I went in, I was blown away. The showroom had a pair of McIntosh hybrid amps costing 17,500 each driving an array of speakers; there were customers with uncontrollable spending habits there telling me about their gear, and about getting in deeper. Quite a showroom with reconditioned, new and some really old stuff more for collectors than users.

Saw the ad...in the meantime the urge go tthe best of me, I now own a set of Cornwall 3's.

This is my version of the Little Sweetie. I'm a ham operator. The output transformer is a military salvage unit which is likely very broad response, originally built for military aircraft. Basically I had all the parts on hand, but cost likely runs to about $30 for me. I have all the components mounted and wil complete the wiring in the next few nights, give a full report soon on my "aural" impressions. I decided to go with a tube rectifier so I can say there is no solid state component in it...I also replaced R10 with a true filter choke with a 200 ohm value, which is more typically how a vintage power supply would have been set up. The tubes are quite common and inexpensive or free. My rectifier is a 5V4 but many would serve the purpose. Put the input jack close to the 6SJ7 to keep the signal path short. Volume control on the left, tone range center, on/off left. The outpout transformer has taps for 4, 8 and 16 ohms so I will be able to run options out to the speaker connect terminal. I will eventuually give an aural comparison of this thing to a Cornwall vs. my McIntosh solid state amp, at least in mono. Since the output transformer is a unique I probably cannot build another one identically, but if this works well I may build matched mono amps.