It is definitely noise/hiss with an irregular component that is also high frequency. There is a very, very small amount of residual hum/buzz, but it is not a problem. The Aleph J is silent enough with inputs shorted.
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post your ref. schm, prepare 2pcs of 100K resistors, and i'll tell you which one (220K) to replace
you'll have 6db lesser gain
you'll have 6db lesser gain
I used the boards from the DIY Audio Store. I believe the schematic should be the same as the one included in 6L6’s build guide…
replace R4 (220K) in both channels with 100K, and you'll have 6db less gain and that much less hissssssssss
if you still have it more than you like , change source
still hoping to see something MF what isn't crap, my heart still and only warm for A1, but even that only after heavy butchery and fan on it
if you still have it more than you like , change source
still hoping to see something MF what isn't crap, my heart still and only warm for A1, but even that only after heavy butchery and fan on it
I like the DAC as compared to the few other cheap DACs that I've had in my system. Stereophile included it in its 2015 recommended components, in Class A no less, which was an anomaly to put it mildly. $299 USD. I can probably do better for some more money.
Would there be any issues associated to putting a 200 Ohm resistor in parallel to R4 on a switch mounted off the board?
oooh, I'm trembling ........ Stereophile!!
heck, even I was in Stereophile, go figure ( they just mentioned my name, no Paper is durable enough to show my Mighty Visage
)
your judgment means to me much more than Audioperiodical's, in this context
now - switching in NFB loop - I would avoid any additional long wires there
I did that few time ( from various reasons and in various gadgets) but always with mini/micro relay ditto on pcb, then wires for relay energizing are irrelevant
heck, even I was in Stereophile, go figure ( they just mentioned my name, no Paper is durable enough to show my Mighty Visage
)your judgment means to me much more than Audioperiodical's, in this context
now - switching in NFB loop - I would avoid any additional long wires there
I did that few time ( from various reasons and in various gadgets) but always with mini/micro relay ditto on pcb, then wires for relay energizing are irrelevant
So that’s the feedback loop, and lowering the resistance in that loop increases the feedback and thereby decreases gain. Thanks for the explanation. It’s probably silly, but I have been working on the assumption that less feedback is better for many years now. I wouldn’t want to permanently increase the feedback of this amp. I can probably put the additional resistor on a switch located on the metal shields I recently added to the amp. The switch would be about an inch away from the PCB. Do you think this would be acceptable?oooh, I'm trembling ........ Stereophile. heck, even I was in Stereophile, go figure ( they just mentioned my name, no Paper is durable enough to show my Mighty Visage
your judgment means to me much more than Audioperiodical's, in this context
now - switching in NFB loop - I would avoid any additional long wires there
I did that few time ( from various reasons and in various gadgets) but always with mini/micro relay ditto on pcb, then wires for relay energizing are irrelevant
I know that you agree that attenuation on the input via a pot is noI desirable, but I found a nice quality 10K pot to try in order to see if it works without adversely affecting SQ. I’ll place it externally and see what happens.
Another possibility is a unity gain tube preamp. While I don’t really have much solid state stuff at hand, I have a mountain of tube circuit building materials. Some sort of buffer, probably using a cathode follower, would be a snap to put together. I can make it super quiet. What do you think?
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Yes, a unity gain preamp (buffer, follower) is exactly what Zen Mod wants you to use.
That’s easy! I’ll put one together. The only question is which one? Time to do a bit of research…
Doesn’t the Aikido have gain? I want something with no gain, very low output impedance and that contributes as little as possible to the sound.
6DJ8/7DJ8, loaded with CCS (ring of 2 bjt good enough, to neg15V)
85-95V rail, 9mA/triode Iq
maybe best both triode sections in parallel, so one bulb per channel
heater elevated to 50V or so
but then you also need proper PSU for anode voltage (shunt reg is my fave; even OA2 is doing the job, combined with SS CCS in front )
killer good sound
is it easier to make than full SS concoction, dunno - it depends of your habits and mental state
85-95V rail, 9mA/triode Iq
maybe best both triode sections in parallel, so one bulb per channel
heater elevated to 50V or so
but then you also need proper PSU for anode voltage (shunt reg is my fave; even OA2 is doing the job, combined with SS CCS in front )
killer good sound
is it easier to make than full SS concoction, dunno - it depends of your habits and mental state
Mental is the right word. What you suggest is easy peasy. I have all the parts for a Bottlehead C4S CCS that fits your suggestion. Why the parallel sections? Also, I have a few 6DJ8/6922, but I have lots of 6N1P-EV and 6N2P-EV. Will a couple of these do in parallel instead? I can do a hardcore linear supply for the PSU. I have lots of different chokes and lots of capacitance on hand (4500uF at 400 Volts for example). Or go with a tube regulated supply? So many choices. It's making me feel a bit light headed...6DJ8/7DJ8, loaded with CCS (ring of 2 bjt good enough, to neg15V)
85-95V rail, 9mA/triode Iq
maybe best both triode sections in parallel, so one bulb per channel
heater elevated to 50V or so
but then you also need proper PSU for anode voltage (shunt reg is my fave; even OA2 is doing the job, combined with SS CCS in front )
killer good sound
is it easier to make than full SS concoction, dunno - it depends of your habits and mental state
Hi tizman, Aikido Cathode Follower actually has no gain. Look it up. It is basically just the second triode of a regular Aikido. I have actually one where I can convert between both versions with just exchanging the first tube for a capacitor.
Drives all my amps with ease … though I still prefer my BA2018 linestage for its superior transparency, gain be damned … 🙂
Drives all my amps with ease … though I still prefer my BA2018 linestage for its superior transparency, gain be damned … 🙂
My 2nd SMPS arrived along with the PSU enclosure so I can get rid of the cooling fan. My single smps had been overheating supplying a constant 200w and needed a fan. I assembled the PSU and re-wired the amp as a dual mono this evening and I am now enjoying some of my tunes. I re-wired it so one channel has just a ground going to the smps. The other channel has the case ground and earth. It is so nice not having to listen to the fan when at low volumes.
Thanks 6L6. I do have to connect the leads correctly so the case GND and earth are not just floating. If I could afford decent 6 way plugs and sockets….. Also thank you for your great guide for building this amp, although I made my own boards it has the same circuit.