No Toobin allowed!i take my eye off the balls for a minute....
No Toobin allowed!i take my eye off the balls for a minute....
My 6SN7's were all used (tested good) or NOS. I had always saved good tubes from discarded TVs and radios, ever since developing an interest in electronics as a kid. I recall getting a supply of NOS tubes at a yard sale when the owner of a TV repair shop died. Ham fests were another excellent source. So I don't really roll tubes, just stick with the NOS that I have. Output tubes are a bit different matter. Originally I purchased a matched pair of Valve-Art KT-88's, the seller included a second pair, one tube of the second set tested good the other was a bit flakey. With separate bias adjustments for each output tube it's possible to run unmatched tubes. I'm sure that distortion is lower with properly matched valves though. I purchased a set of four generic Chinese tubes for the other amps. I found that the Chinese tubes needed bias readjustment much more often, in addition they became weak and I even had to change resistor values to be able to set the bias properly. I included test jacks on each amp one per tube, I just have to plug in my multimeter to adjust the bias. I run about 40 mA per tube, and adjust so that both sides read the same. A year or two so ago I purchased a matched quad set of JJ/Tesla KT88s. I put them in the top amps (front channels) while moving the Valve Arts to the bottom two amps replacing the Chinese ones. More recently, (earlier this year) I purchased a second set of JJ/Tesla KT88s to replace the Valve Arts. The bias setting is much more stable now!That’s clearly a very impressive setup you have there. Please tell us about your experience with tube rolling and replacing and bias matching tubes. I would imagine that it can get quite warm down there.
Thanks for sharing your experience with your tube setup. I would imagine that the overwhelming majority of us here, myself included, have solid state systems based on home theater receivers, preamps and processors. However, it's fun to read about how tube system owners tweak and maintain their setups. Regarding the heat dissipation, I hadn't taken the Canadian factor into account!My 6SN7's were all used (tested good) or NOS. I had always saved good tubes from discarded TVs and radios, ever since developing an interest in electronics as a kid. I recall getting a supply of NOS tubes at a yard sale when the owner of a TV repair shop died. Ham fests were another excellent source. So I don't really roll tubes, just stick with the NOS that I have. Output tubes are a bit different matter. Originally I purchased a matched pair of Valve-Art KT-88's, the seller included a second pair, one tube of the second set tested good the other was a bit flakey. With separate bias adjustments for each output tube it's possible to run unmatched tubes. I'm sure that distortion is lower with properly matched valves though. I purchased a set of four generic Chinese tubes for the other amps. I found that the Chinese tubes needed bias readjustment much more often, in addition they became weak and I even had to change resistor values to be able to set the bias properly. I included test jacks on each amp one per tube, I just have to plug in my multimeter to adjust the bias. I run about 40 mA per tube, and adjust so that both sides read the same. A year or two so ago I purchased a matched quad set of JJ/Tesla KT88s. I put them in the top amps (front channels) while moving the Valve Arts to the bottom two amps replacing the Chinese ones. More recently, (earlier this year) I purchased a second set of JJ/Tesla KT88s to replace the Valve Arts. The bias setting is much more stable now!
As for the heat, I don't mind. The basement stays cool even in summer and in winter the more heat the better! Although it's melting now we already have snow in the ground!
Your profile says nothing about Marantz or Pioneer. Emotiva? Oppo( there it is on the left) and where is the Denon AVR?
Gear porn, I am getting faint with vapors ♨
I have two main systems; my “original” is now in the basement in my man cave. Both systems are bi-amped. My Man Cave set up uses tubes for the mid/high and solid state (mos-fet) for the bass.
I call it my “Wall of Tubes”. The entire rack is all homebuilt. The tube amplifiers came about from a design from Acrosound, shown in an old publication supporting their line of Ultra-Linear Output Transformers. Its design was beautifully balanced from input to output, incorporating excellent sounding octal tubes 6SN7 and one 6SL7 in the driver stage. You can find it here. http://www.tubebooks.org/file_downloads/acrosound.pdf
I had previously been given a box full of 6146 transmitting tubes; Acrosound had an amplifier design that used them. I doubt that the specified transformer is available anymore (Acrosound TO-350), it has a separate winding for the screen grid. I didn’t even bother looking for it but opted for a more conventional and readily available Hammond Transformer which is made in Canada! My transformers have a tap for the screen grids rather than a separate winding. The original 6146 design runs 725V on the plate and 220V on the screen grid. I thought that I could make it work with a fixed voltage on the screen grid and running a more conventional 500V on the plate. It would then run as a triode rather than in ultra-linear mode producing much less power but that would still be OK. Well I had trouble getting it to function correctly. I decided to try more conventional output tubes instead, I put in a set of KT-88’s which worked out fantastic. Further refinements included regulating the supply voltage to the driver stages, while leaving the plates unregulated. I tweaked the feedback RC network for best square wave response, and ran feedback around both sides the way that AR does. A switch was added to connect the screen grids such that the amplifier can run in ultra-linear mode or triode mode. Triode mode gives less power but reportedly better sound. The two chassis below contain power supplies for the four amplifiers one for each pair. They contain different transformers but are functionally the same.
The bottom two silver boxes have been in my system since the late seventies. The bottom box contains four +/- 45 Volt power supplies, (quad mono). The smaller box originally contained eight ILP 120W amplifier modules. Four were for bass the other four for mid/high. Latter I add four more IPL modules, they sported mosfet output transistors. They only put out 60W each but sounded better than the bi-polar’s, I used them for the mid/highs. The bi-polar amps were then bridged for even more bass output power.
I used to be able to boast about having a 1200W stereo system! People would say “Oh it must be really loud”, I would have to explain that it’s like having a big V8 in your car; it doesn’t mean that you are going to drive it wide open all the time. It just gives you extra power (headroom) for passing and hill climbing, same with audio. That argument might now carry a bit less weight given the sorry state of today’s overly compressed audio! Given the number of output channels in some of today’s home theatre systems, I’m sure that kind of power is not unheard of though, it adds up fast!
Shortly after becoming a reader of “Glass Audio” and “Audio Amateur” I decided to build “A Sixty Watt Mosfet Power Amplifier” by Erno BorberlyView attachment 58341View attachment 58342View attachment 58343ly. The project was greatly simplified by purchasing the circuit boards from “Old Colony Soundlab”. The amps sound very good indeed and have proven to be very reliable, over the years. I originally configured them for the mid/high frequencies but now use them for the bass with the tube amps driving the mid/high speakers. The Borberly amps now reside in the smaller silver box in place of the ILP modules. The View attachment 58341amps described here were originally part of the Living Room system, due to the size of the tube amps they were placed in the basement. The long feeder lines made the use of balanced interconnects necessary. The amps were/are turned on and off by means of solid state relays and a 12V control wire connection.
I’m afraid can’t begin to compete you @par4ken in terms of power, nor commitment to DIY valve builds (I’m not that good at all the chassis metal work they tend to involve). Nonetheless, I’ve always had a passion for valve based equipment. In addition to my recently acquired OCTAVE V80SE Integrated Amp which is now the heart of my main system, I’ve currently got the following valve based items in various systems dotted around the house:I have two main systems; my “original” is now in the basement in my man cave. Both systems are bi-amped. My Man Cave set up uses tubes for the mid/high and solid state (mos-fet) for the bass.
I call it my “Wall of Tubes”. The entire rack is all homebuilt.....
More to come!Just amazing. A lot of smarts, labor & passion went into that project. And all in a nice 19" wide package! It was good to hear you drop names like Old Colony, Borbley, Audio Amateur. I inherited a stack of older AUDIO magazines circa mid-50's> mid-60's. It was an exciting time for HiFi then. There were more articles on tube gear than solid state & I learned a bit & enjoyed reading them. Still no hands on for me building tube gear. Oh except for a Knight Kit BCB xmtr.
I feel these pics are only the tip of the iceberg. Hey where's all your decoders like the Photolume & other quad stuff? I'd like to get a look at your electro-workbench where all this stuff is built.
Yeah, though I never attempted to build one, I remember when Heathkits were all the rage.Just amazing. A lot of smarts, labor & passion went into that project. And all in a nice 19" wide package! It was good to hear you drop names like Old Colony, Borbley, Audio Amateur. I inherited a stack of older AUDIO magazines circa mid-50's> mid-60's. It was an exciting time for HiFi then. There were more articles on tube gear than solid state & I learned a bit & enjoyed reading them. Still no hands on for me building tube gear. Oh except for a Knight Kit BCB xmtr.
I feel these pics are only the tip of the iceberg. Hey where's all your decoders like the Photolume & other quad stuff? I'd like to get a look at your electro-workbench where all this stuff is built.
Totally awesome! I lived very close to the big Allied Radio store on Western Ave in Chicago for many years and I built a number of Knight Kits back in the day. I also built a illegal linear amp for my CB using a pair of 6146B output tubes, think it did about 80 watts AM and quite a bit more in SSB.I call it my “Wall of Tubes”. The entire rack is all homebuilt.
Totally awesome! I lived very close to the big Allied Radio store on Western Ave in Chicago for many years and I built a number of Knight Kits back in the day. I also built a illegal linear amp for my CB using a pair of 6146B output tubes, think it did about 80 watts AM and quite a bit more in SSB.
I do miss my old tube HiFi in Chicago, maybe not super accurate but sweet sounding none the less. VTL 100 monoblocks into Klipsch La Scala's and NAD SS 300 watt monoblocks driving a pair of 7' tall early HSU subwoofers. (CA 1994) Look up "dynamic" in the dictionary and your see a picture of that rig. But here's a poor one of mine anyway. LOL You can also see a Dynaco ST70 sitting in reserve on the right shelf.
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Some years before the VTL tubes (CA 1980) I had Crown IC150 preamp and Phase Linear 700B power. The neighbors were not friendly. LOL
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Reaching back to my first real HiFi + multich was my Marantz 2270 receiver and 2440 quad adapter driving MicroAcustic speakers.
Livin' on reds, vitamin C, and cocaine
Lately, it occurs to me
What a long, strange trip it's been
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Me too. LOLI remember in the 70's when friends faces at a party actually looked like that...
Of couse, in the early 80's, when money was tight.....the seeds were a stash out of desperation. Grind em up and light em up. Ugh....the taste was horrific.I love these old pics....a much different time...for sure...I can remember going to the local market and getting those wooden crates that held produce in them and staining them to make speaker stands and hold LPs in....and of course the LP's were used to separate the "stems from the seeds" by tilting them and letting gravity take care of the seeds
Of couse, in the early 80's, when money was tight.....the seeds were a stash out of desperation. Grind em up and light em up. Ugh....the taste was horrific.
And... Deja Vue was my go to album in my lap for rolling with a Rizzla.I did that too...but I saved those for my bong filled with cold wine...it cut down on harshness
Absolutely! Only my friend and I used ice water. hahaha.....I did that too...but I saved those for my bong filled with cold wine...it cut down on harshness
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