What is the benefit of modifying/building/designing a pre to have a 2 - 10 ohm output impedance specifically for an amp that has 100K input impedance?
6C33 - IIRC, that is the tube everyone always raves about for a Cyclotron Output-transformer-less amp - low voltage high current, correct?
6C33 - IIRC, that is the tube everyone always raves about for a Cyclotron Output-transformer-less amp - low voltage high current, correct?
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Did some readings last night:
B+ to G = 230VDC
G to H+ = 65V
G to H- +53v
B+ to H+ =150v
B+ to H- = 162V
Across R17(1.5K ohm) 322v to 232v
These two Caps are to never exceed 150V
c6 = 173v
Across R5, Voltage should read significantly lower on one side:
Reads 231vac
C21 = 228
C8 = 319
c11 = 229
C22 = 95
C12 = 97, not exceed 160v
the heater voltage works fine. Using the Voltage doubler and get 12.6v all the way to the C25.
Should I increase the B+ to 300V? I guess lowering the value of R17 should get me there?
B+ to G = 230VDC
G to H+ = 65V
G to H- +53v
B+ to H+ =150v
B+ to H- = 162V
Across R17(1.5K ohm) 322v to 232v
These two Caps are to never exceed 150V
c6 = 173v
Across R5, Voltage should read significantly lower on one side:
Reads 231vac
C21 = 228
C8 = 319
c11 = 229
C22 = 95
C12 = 97, not exceed 160v
the heater voltage works fine. Using the Voltage doubler and get 12.6v all the way to the C25.
Should I increase the B+ to 300V? I guess lowering the value of R17 should get me there?
lol. just double checked everything on the pad and sure enough. The R17 bag was labeled 1.5k and its actually a 3k resistor, which should explain why there is a 90 Volt drop across the resistor instead of a 45-50v drop.
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HA HA!!! Yes, after that I double check all values from Broskie's kits...I can see how it happens and surprised it doesnt happen more often...
Must be ones packed late at night and after a couple brews....
Long live Late nights and Cold BREWS!!
I guess I'll order some kiwame resistors from Parts Connexion. might as well order replacement for R15, R16, R17, R19 since they are sonically important..
Hi,
I finished my build and all is good except for the low frequencies. Everything is sounding good but there's a serious lack of bass. My first guess is the output caps. I have 0.47uf caps in the C1 position. Maybe these a too small?
What numbers do I need to calculate the value the coupling caps should be?
I read that you need the load input impedance but i'm not exactly sure what this is/how to measure.
Can somebody shine some light on this?
tnx
edit: i'm feeding a rega mira power amp and the manual says: Power amplifier input sensitivity = 818mV. load 24KΩ
I finished my build and all is good except for the low frequencies. Everything is sounding good but there's a serious lack of bass. My first guess is the output caps. I have 0.47uf caps in the C1 position. Maybe these a too small?
What numbers do I need to calculate the value the coupling caps should be?
I read that you need the load input impedance but i'm not exactly sure what this is/how to measure.
Can somebody shine some light on this?
tnx
edit: i'm feeding a rega mira power amp and the manual says: Power amplifier input sensitivity = 818mV. load 24KΩ
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I use the dual mono octal boards with the janus regulator from tubecad.
6sn7 tubes in all positions.
I just soldered a 2.2uf cap I found in parallel with the 0.47uf caps and bass is much much better. But now, the amp is very sensitive to vibrations. When I knock on the amp, I hear it loudly through the speaker, something I haven't noticed before. I read this can happen when there's too much capacitance in the output caps?
Any thoughts on caps or other parts I should check?
thanks
6sn7 tubes in all positions.
I just soldered a 2.2uf cap I found in parallel with the 0.47uf caps and bass is much much better. But now, the amp is very sensitive to vibrations. When I knock on the amp, I hear it loudly through the speaker, something I haven't noticed before. I read this can happen when there's too much capacitance in the output caps?
Any thoughts on caps or other parts I should check?
thanks
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2 6SN7's in the aikido will yield only about a gain of 9. That is rather anemic depending on what you are driving with it.
I am driving a MOSFET driver stage (Moskido) with an octal aikido 6SL7 input and 6SN7 output. It may be more gain than you want but personally I would rather have the headroom and not need it.
I am driving a MOSFET driver stage (Moskido) with an octal aikido 6SL7 input and 6SN7 output. It may be more gain than you want but personally I would rather have the headroom and not need it.
8 x 6N8S 6CC10 6SN7 tubes Military FOTON NOS 1960s items in Retail tubes store store on eBay!
ebay store with tubes, expect to wait a month though.
ebay store with tubes, expect to wait a month though.
....you are looking at the 'Type II'...., which does have 100K unbalanced, .....however, .... mine is the 'Type I'..., which has 1K unbalanced. How do I know? I was directly informed by the designer himself.
