fini Posted March 13, 2008 Share Posted March 13, 2008 Is this bigger....? OK, I get it, the forum software automatically sizes the image. Sorry about that. I ran into this thread while searching for "is this bigger." When you click on the graph, it gets bigger (opens a new window). If it gets too big, you may have to open all the windows. Quote Link to comment Share on other sites More sharing options...
WopOnTour Posted March 16, 2008 Share Posted March 16, 2008 I definately agree as far as the Hammond universal 125SE series trannies go. I had originally purchased the 125ESE for my JE Labs 300B\2A3 DX, but found those trannies "wanting" actually at both ends of the scale. So I went out and purchased a pair of Hammond 1627SEA (potted and 11lbs each) and was VERY pleased with the results. Much better bass and upper range extension compared to the other less expensive Hammonds. But these wernt even that much more expensive ~$100 each http://www.hammondmfg.com/1627.htm WopOnTour Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted March 16, 2008 Share Posted March 16, 2008 Good to hear something positive about the Hammond OPT. There is a variety of opinions on the various forums about them. The James are about the same money: http://euphoniaaudio.netfirms.com/ea/nfoscomm/catalog/index.php?cPath=26_1_33&osCsid=a7f02a1d4d185151de8fb722d0cac0ac Yesterday I put my diy 45SE (SRPP) back with some open baffles (10"full range + 15" woofer/Lpad) and they sounded real fine, this amp uses the James 6112HS, very nice, with plenty of bass. Didn't work last time I tried it. Maybe I had the wrong impedance on them before or maybe it was the different set of 45 tubes I put in there. I used the 4 ohm tap since the two speaker components are in parallel. Meanwhile the DIY JE Labs SE 300B DX with Sowter OPT is the heart of my triamp system which is now using all tubes. I put the upgraded Dynaco Mark III on the bass and a modified Dynaco ST-70 on the high frequencies. This system really works for me and the added SE in the middle has made it better than ever (with presence and brightness to spare). I can adjust so that a lot of the middle comes through the legendary Altec 515. It is not about loudness, it is about there being some there there. Between the 3-way active crossover and the Aphex aural exciter, I can tweak almost any recording so that there is there there. This gives me the level of engagment in the music that I desire. This is my preferred system and where most of my vinyl collection lives, and it is plenty resolved and focused for me with great sound stage. The small residual hum (after hum pots are trimmed) is something I can live with. There are kind of a lot of tubes going in this system! When I want open baffles, I have another space where I can experience them as well (now with some nice SE 45tubes) . In yet another room I have the proto pCats on a pair of diy Altec Valencias, another good match. So I think things are settled for awhile, nothing is ever absolutely perfect but I am at peace with it now and need to change emphasis to some other projects....ok maybe some fun tube rolling with the drivers for the 300B just for jollys and because I can. Soundwise: there is there there...... btw, building these simple diy SE tube amps is a fun and rewarding activity in and of itself....rainy day stuff..... -? ? ? (©fini) Quote Link to comment Share on other sites More sharing options...
WopOnTour Posted March 16, 2008 Share Posted March 16, 2008 Well I mounted both the 166L5 and 166L2 heater supply trannies under my chassis, and wired the Angela PTX secondaries so I can easily swap between the 300B and 2A3 with a flip of a switch.(well technically two) Works good! While I much prefer the results with the 1627SEA outputs over the 125ESE (I have these on my bread-boad system now) I see Hammond is now offering a larger version of these open OPTs, the 125GSE that looks like could more safely handle the 80mA cathode current operating point that I prefer. http://www.hammondmfg.com/125SE.htm They're DOUBLE the weight of the ESE and are rated to 100mA! Maybe I'll try a set and see how they compare... one cant have too many trannies (eeww! Did I say that?) WOT Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 16, 2008 Share Posted March 16, 2008 Took a gamble and snarfed a batch of untested tubes on CL locally. There was a couple 45's in there, with a pair of 71A's. I knew there was a high probability of the old triodes being wanked, but I prayed to the thermionic gods anyway and hoped. Both 45's had open grids, and a 71A as well. Oh well.........I did get some strong 6V6 and some rectifiers.....5Y3's.....a globe Cunningham CX-381 half-wave rectifier that has strong emission.....too bad I didn't have two. I guess it wasn't a total gyp..... One 71A is strong. And I have a 71A I saved from the garbage that tests like new. So I may as well breadboard up a circuit with 71A. Should be enough to power LaScalas. The little single-ended 6BQ5 pentode Magnavox console pushes them to rather moderate volume in my smaller room. I can use the Lambda regulated DC tube PS for the B+, and the heaters for a six volt driver/drivers. Dunno how many 6SL7 I have laying about. I know I won't live with 5 volts AC heating with 71A, maybe with a null pot....I do have some regulated 4 volt or wherabouts DC supplies. I series wired two together to try to swing the filament current/voltage for a pair of 801A's. It would swing one, but would draw too much current and kick the overload protection on the supplies when powered up. I should be ok with 71A, being less filament V/I. I have the 6123HS output transformers to try, or some vintage single-ended 6BQ5 OPT's. I may try that after I finish this second Maggotbox 6BQ5 SEP console amplifier. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted March 16, 2008 Share Posted March 16, 2008 Mike, I stopped over to see fini and he has the makings of a Maggotbox as well, also some encouraging notes from you, very impressive notes I must say! He says you like that little SE 6BQ5 amp too. I bet his Khorns would sound great if he gets that amp up and running and follows your directions. I have been hearing good things about that old 71A, the ultimate flea circus. The JE lab guy seems to like them. Think I will sit that one out because I have enough projects right now. Not sure, but if I have any lying around in the radio junk box, I will send them your way. Have you done anything with 6V6? PP or otherwise? The old amps in 16mm movie projectors used them, but that was for amplifying that light strip on the edge of the film. Seems like they used a lot of 6v6 for various lower powered amps back in the day.... I think I am going to enter into a little breadboarding myself, for educational purposes, and also to eventually make a 45 SE amp with and for fini, and possibly an equivalent 46 amp for me. For starters I want to see what kind of power supply I can make from existing "junkbox" parts, nice junk though, fini premium county dump junk finds. Should be a good learning project. btw, I checked with fini and he doesn't really have any scavanged opt's, lots of organ power transformers, but not so much on the output iron, except for 88 little tuneable organ transformers of some kind, each with its own 12AU7! I have no idea what those things are or do or what they would be good for. I should keep my eyes peeled for one of those Maggotbox possibilities, seems like a fun one.... C&S Quote Link to comment Share on other sites More sharing options...
WopOnTour Posted March 16, 2008 Share Posted March 16, 2008 Those are probably small inter-stage transformers for the 12AU7s. I've seen a few old organ amps that used inter-stage coupling instead of caps and/or grid stoppers.Do they plug right into an octal socket?? I've never heard a 45 amp but sure would like to! What equipment were they most prevalant in?? WopOnTour Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted March 16, 2008 Share Posted March 16, 2008 I restored a 1920s Atwater Kent tube radio with a beautiful wooden cabinet that fini found at the dump, the output tube in there is a 45. It is an old radio tube triode power tube that sounds pretty nice even on that old electromagnetic speaker! A few years ago they were plentiful, now they are prized by SET guys and the price went up and the Chinese started making them again. C&S That organ amp section looked like every note on the organ had its own little 12AU7 and a transformer. I cannot remember if they plugged in or not, they were not potted and they had some kind of adjusting thing on top. Those are probably small inter-stage transformers for the 12AU7s. I've seen a few old organ amps that used inter-stage coupling instead of caps and/or grid stoppers.Do they plug right into an octal socket?? I've never heard a 45 amp but sure would like to! What equipment were they most prevalant in?? WopOnTour Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 16, 2008 Share Posted March 16, 2008 Mike, I stopped over to see fini and he has the makings of a Maggotbox as well, also some encouraging notes from you, very impressive notes I must say! He says you like that little SE 6BQ5 amp too. I bet his Khorns would sound great if he gets that amp up and running and follows your directions. I have been hearing good things about that old 71A, the ultimate flea circus. The JE lab guy seems to like them. Think I will sit that one out because I have enough projects right now. Not sure, but if I have any lying around in the radio junk box, I will send them your way. Have you done anything with 6V6? PP or otherwise? The old amps in 16mm movie projectors used them, but that was for amplifying that light strip on the edge of the film. Seems like they used a lot of 6v6 for various lower powered amps back in the day.... I think I am going to enter into a little breadboarding myself, for educational purposes, and also to eventually make a 45 SE amp with and for fini, and possibly an equivalent 46 amp for me. For starters I want to see what kind of power supply I can make from existing "junkbox" parts, nice junk though, fini premium county dump junk finds. Should be a good learning project. btw, I checked with fini and he doesn't really have any scavanged opt's, lots of organ power transformers, but not so much on the output iron, except for 88 little tuneable organ transformers of some kind, each with its own 12AU7! I have no idea what those things are or do or what they would be good for. I should keep my eyes peeled for one of those Maggotbox possibilities, seems like a fun one.... C&S Gregg needs to get that little 8600 series Magnavox fired up. I'll send him pics of wiring layout of my current Maggotbox project if it gives any encouragement. My other Maggotbox sounds good on Cornwalls, and my cobbled-up LaScala's. I couldn't see it sounding bad on Klipschorns. In fact, I wouldn't doubt the little 8600 series Magnavox 6BQ5 SEP console amp would fare rather good with the little Tekton(SP?) FR jobbies. I used a pair of old Motorola "Golden Voice" FR 8" drivers with whizzer cones in open backed bookshelf enclosures with the amp, and it didn't really sound that bad. Nothin' I could ever live with, but the little amp seems balanced enough to sound good on about anything that's efficient enough.....'cept Polk monitor 10's.....eww... I never have tried 71A, it might be interesting. Maybe we can work out some sort of Barter deal if you find 71A's.....If these two here float my boat and sound magical, I can always just pony up for some more.... 6V6 sounds good in single-ended pentode mode to me. Never tried PP 6V6, but I'm certain that sounds nice too. It's kinda like 6BQ5 sound, but not as sharp. I set up a breadboard circuit as the classic textbook example self-biased, 250 volts on the plates and screens, driven by a 12AX7. I used the 5K tap of the James 6123HS OPT, with a little feedback from the secondary to cathodes of 12AX7...can't recall the value. Not bad......I also have a pair of Ampex EL-84 SE OPT's from a tape recorder or something.....I recall these even sounding better with 6V6 than the James. A little less bass than the big 20 watt James, but it made the 6V6 sound more like a triode sound. If you scratch build amplifiers and experiment with different circuits/topologies, a breadboard is the way to go. You can pick a circuit of interest, cobble it up on a breadoard. Use a external DC tube PS to power the circuit, or build a PS to use with the circuit. If one likes the circuit, then one can go ahead and tweak as necessary. Then one can go ahead and design and build a PS for the circuit, and move on to a finished amplifier. This saves the hassle of building a finished amplifier circuit without testing or tweaking. Only to have problems or disatisfaction with the circuit and have to tear it all apart again. A guy could build a project amp with circuit topology unheard, and going by hear-say. In the end he doesn't like the sound........using a breadboard it would have never gotten that far. The 196 series Magnavox console would be a good find. These use a 5U4 with a choke, and a 12AX7 driver. They have stronger bass as well. Apologies to Jim for ripping off his pic..... Quote Link to comment Share on other sites More sharing options...
WopOnTour Posted March 16, 2008 Share Posted March 16, 2008 Totally agree about the bread board thing, only way to learn what works and what doesnt is to mess around (safely of course) and "fry" a few things LOL Speaking of EL84 PP amps I won this one yesterday... http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=300205598807 I decided to bid up to $150 on it because of the local pickup, plus I liked the looks of those transformers and if I'm not mistaken those Motorola branded grey plate tubes are Holland Amperex (D-getter?) I havnt owned an EL84 amp since I sold my pair of HK A10 Allegros and I miss them! The wiring is a total mess, no fuse or switch, 2-bit speaker and RCA jacks, crappy caps,no volume control and a ridiculous ground scheme but give me a Sunday or two with it.... WopOnTour PS> Here's an item I picked up locally at an auction for $50 that REALLY aids in my bread-boarding Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 16, 2008 Share Posted March 16, 2008 That's a good score. I'm just stuck with the lowly Lambdas........25 bucks for the top tube regulated supply. It's only good for 350VDC at 200 mils, but it's wonderful piece of overbuilt 50's technology. No 'lytics...all oils and chokes with original strong testing tubes. He threw in the 10 amp 35 volt PS as well. That thing weighs a good 100 pounds.... Quote Link to comment Share on other sites More sharing options...
fini Posted March 17, 2008 Share Posted March 17, 2008 I should keep my eyes peeled for one of those Maggotbox possibilities, seems like a fun one.... Folks are on to it: Maggotbox 1 Maggotbox 2 Best to keep an eye out at St. Vincent de Paul, etc., IMHO. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted March 17, 2008 Share Posted March 17, 2008 One might also make just the amp section from scratch. I don't think those output trannies are that hard to find, or their equivalents. But I agree, thrift store or dump find might make for a good story. c&s Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 18, 2008 Share Posted March 18, 2008 One might also make just the amp section from scratch. I don't think those output trannies are that hard to find, or their equivalents. But I agree, thrift store or dump find might make for a good story. c&s I was going to mention that too........scratch building. The circuits are so simple that it wouldn't be difficult at all. Edcor makes single ended output transformers for SE 6BQ5. I never have used them, but they seem reasonably priced. I doubt anyone will bite for the 200 dollar BIN on the Magnavox #1 8600 amplifier listing....a little rich to me. Mine's gotta be worth that much.... Note the blue cap riding shotgun on the second Magnavox listing...... Quote Link to comment Share on other sites More sharing options...
fini Posted March 18, 2008 Share Posted March 18, 2008 Mike, I like that: Riding shotgun. What a crack-up. Maybe you'd better send me a couple under-chassis shots for inspiration. I'm finally getting off my rump to put together a step-up transformer, using Altec 4722s. C&S was kind enough to lend me his to copy, and bring over a lot of teflon-coated silver plated hookup wire. It's finally time to fire up that NIB Hakko!! Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted March 18, 2008 Share Posted March 18, 2008 fini, I sometimes use a silver pencil to note the pin numbers of the octal sockets underneath the chassis as a handy reminder. For security reasons, don't let the other socket know the PIN number of the socket you are working with. Ok, that was a joke. I have a box of these pencils if you need one (I also use them for marking dark metal for cutting etc., more precise than the "chalk" markers that welders generally use) and it rubs off easily. you remember the old saying..... ..... Ihr kleid kam schneller als die weiße Markierung auf einem echten Telefunken 12AX7 ab. (eg....her dress came off more easily than the white markings on a real Telefunken 12AX7......... ) You can see the numbers on the octal sockets themselves but they are hard to see sometimes and things get confusing if and when you have different orientation for the sockets and sometimes it is possible to make little mistakes (with bigger consequences). They are numbered clockwise (1-8), seen from underneath, starting at the locking pin, which I do realize you already know. --Catsup & Mustard Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 19, 2008 Share Posted March 19, 2008 Mike, I like that: Riding shotgun. What a crack-up. Maybe you'd better send me a couple under-chassis shots for inspiration. I'm finally getting off my rump to put together a step-up transformer, using Altec 4722s. C&S was kind enough to lend me his to copy, and bring over a lot of teflon-coated silver plated hookup wire. It's finally time to fire up that NIB Hakko!! Somebody snagged that first Maggotbox listing for the opening bid of $150. 150 bucks for a bone stock single-ended console amp...... You'll have to PM me with your email address.....I lost it when my last PC died. Good luck with the step-up x-former project, I have some teflon coated plated wire pinched from a Gates console. I used a bit in the current Maggotbox project. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted March 19, 2008 Share Posted March 19, 2008 C and S: I'm interested in the Atwater Kent you restored. I have one, too, from that approximate time period but it uses 01As. One of its output transformers was internally shorted, and it was a potted thing encased in tar. A pain to work with. I pried all the gunk out, and was able to fit a modern replacement inside it, and repotted with hot glue. Right now it's being used with a Radiola horn, but I would really like to get an AK horn for it, My dad has a collection of these old radios, and the AK horn was a big improvement as far as improvements go for those old, slightly tinny sounding horns. Still, we wouldn't be where we are right now if not for them. I'm using the battery replacement power supply kit from AES, but am going to change to series connected 12 volt cells that will be tapped for the different voltages needed -- plate, filament, etc. What supply are you using with the AK you restored? BTW: Transcendent Sound has a new stereo amplifier out now, with an output in keeping with about a 2A3. It's a cathode-follower design, and like everything he designs, looks promising to me. It's less expensive than some other things now available, but is least complete, including chassis. His SE OTL is among the very best amps I have or heard, regardless of cost and power output (which is in line with a 45). The cathode follower amplifier is not an OTL, however is described as having all of the good traits of conventional single-ended with air-gapped OPTs, but with much improved bass response. http://www.transcendentsound.com/cathodefollower.htm Erik Quote Link to comment Share on other sites More sharing options...
johnyholiday Posted March 19, 2008 Share Posted March 19, 2008 What is the power of the 6B4G? I know 2A3 is usually around 3 or 3.5 watts.[8-|] Quote Link to comment Share on other sites More sharing options...
johnyholiday Posted March 19, 2008 Share Posted March 19, 2008 Totally agree about the bread board thing, only way to learn what works and what doesnt is to mess around (safely of course) and "fry" a few things LOL Speaking of EL84 amps I won this one yesterday... http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=300205598807 I decided to bid up to $150 on it because of the local pickup, plus I liked the looks of those transformers and if I'm not mistaken those Motorola branded grey plate tubes are Holland Amperex (D-getter?) I havnt owned an EL84 amp since I sold my pair of HK A10 Allegros and I miss them! The wiring is a total mess, no fuse or switch, 2-bit speaker and RCA jacks, crappy caps,no volume control and a ridiculous ground scheme but give me a Sunday or two with it.... WopOnTour PS> Here's an item I picked up locally at an auction for $50 that REALLY aids in my bread-boarding [8-|] original form on right Quote Link to comment Share on other sites More sharing options...
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