Buy the way, this box of parts came with 5 new ECC99 tubes. Has anyone use the on these boards?
I have them as output tubes in my build. Input tubes are 12AU7. Looks like you have mono boards—go dual mono? There's a ton of tube specific and voltage specific resistor choices/settings. Definitely try to obtain PSU and Aikido manuals from John for what you have. And also see if you can find out from the original owner what they were planning—since the boards are already populated with who knows what?
John also makes a select switch specifically to switch between (and combine) C3a and C3b caps. "Stero-Freq" I think it's called. I mounted it on the back panel of mine. Pretty cool. (Actually, It looks like you might have that... I think I see it peeking in one of the pics...?)
John also makes a select switch specifically to switch between (and combine) C3a and C3b caps. "Stero-Freq" I think it's called. I mounted it on the back panel of mine. Pretty cool. (Actually, It looks like you might have that... I think I see it peeking in one of the pics...?)
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That is a 2 position selector switch in the pix. I may use that or the 4 position out of that box. The Janus Regulator board is finished and the mono boards only have a few resistors soldered in.
Is John the Glass Audio guy?
Is John the Glass Audio guy?
Yes, John Broskie. His circuit—and general awesomeness.
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The "2 position" switch is really 3... I only ever have 2 sources at this time. DAC and Turntable. So position "1" is no switch then "2" clicks to the right... 3 pairs of RCAs.
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Printed Circuit Boards and Kits
The "2 position" switch is really 3... I only ever have 2 sources at this time. DAC and Turntable. So position "1" is no switch then "2" clicks to the right... 3 pairs of RCAs.
That's the "Stero-Freq" switch. Goes with C3a and C3b on the outputs and switches between the 2 caps, per mono board.
Output-capacitor Selector Switch and PCB
Output-capacitor Selector Switch and PCB
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John mentions something about bass effects (In the Aikido Noval manual, not what you have.)... but it really depends on what the caps are. I think it's cool to put in different options... and hear what's what...
I've read many times in my research that these boards have a lot of gain. I wonder if I could use that switch to from normal out to a gain lowering circuit?
My limited understanding is the gain in this amp is a function of which input tubes (there's quite an exhaustive chart of all of this in the manual, output tube choice will reduce the gain a bit) at what B+ voltages. I'm having zero issues in my system, as far as I can understand, with gain. Someone made a comment about the Aikido having too much gain—I'm not sure I know what that would "sound?" like or what effect that would have (noise? distortion?). "Gain" in my current system: phone-pre (MC cart, ~60db) --> Aikido (~18db) --> M2X (~15db) --> sensitive speakers (I can hear the faintest hush with ear to cone which I attribute to the tubes—since If I swap the Aikido for a solid state pre—Wayne's BA18 Pre—the hush is gone, Wayne's has less gain as populated, sooo?). The Aikido setup is the best my system has sounded, to me, to date. I can tweak the "sound" with cart changes, and input stage changes on the M2X, both of which make subtle to big differences, but really just makes me want to run 2 arms. 😀
the amp I am going into is only 5wpc so the gain my be good. Here are a couple pages from the manual. which tube arrangement should I use for the ECC99 tubes I have.
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To simplify my understanding, I trusted the designer... I followed the recipe right off the product page for my board which in my case was 12AU7 input and ECC99 output at 12VDC for heaters and ~250VDC B+. The challenge being sorting out transformers (PS21 PSU). You need to decide on your voltages, based on transformers and design visuals... and likely that will inform the rest—and you may end up limiting your tube choices inevitably—also looks like some stuff is stuffed on your boards—and several of those resistor spots are tube specific... Looks like you have choices in pairing up the ECC99 since it looks like it can run at multiple voltages... presumably there are audible differences between all the combos. Makes me want to build another one too hear!
JJ Electronic - ECC99
JJ Electronic - ECC99
I was going through the manual and saw this highlight in the headphone section. Maybe the guy who was building this was going to use it for a headphone amp.
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another question. I have three chassis stacked and will have the input on the bottom chassis with the 4 position selector switch and from there the selected input will go up to the two signal chassis and into volume pots and the output will be on both the signal chassis. I'll run the two volume pots with a dial on the bottom chassis by chain up to the two volume pots.
So what are good volume pots? I don't want to go crazy but would like something respectable.
So what are good volume pots? I don't want to go crazy but would like something respectable.
That sounds awesomely insane. I don't have a ton of experience with pots? In the following order: Alps blue velvets—no issues, have tried motorized versions. Got a deal on a linear TKD and did the resistor shunt mod, I think it was overall better than the Alps. Most recently—in this thread—installed a Muses based pot. That is 100% worth the effort in my opinion.