telefunk said:Ideas to improve the PSU design? Anybody?
You could get rid of the zeners and the (possible) switching noise, and use bigger value R5 to achieve the right B+. That may lead to capacitor popping voltage unloaded though.
Changing the 1G grid to ground to 200M -> less (sub)bass.
Measurements done with a load?
pasarski said:BTW, I'm not sure if it fits the capsule mount in your mic but I highly recommend Tim Campbell's CT12.
telefunk said:-Pattern voltages are:0v-51,6v-105,8v (but i'm aiming at 0v-60v-120v) coming from the PSU.
What's the diode for?evil grill said:Howdy!
Since Retro Tube II is really cheap now I have bought 2 that I will try to improve.
I would apprechiate help identifying problems with my plan.
See attached schematic.
abbey road d enfer said:What's the diode for?
PRR said:> Saving the life of the tube at start-up.
Not with 51k in series. 98% of stray current flows in grid, 2% in diode. Stray current is a mA at most which won't hurt the grid.
What is in fact wrong with the mike as-is? If you just want a change to have a change, paint it purple. Color can have a large effect on sonic perception. (I wish I still had my brass microphone but it needed constant buffing.)
Where is R11 in the schemo? Do you have a better schemo than this one, which has several mistakes.I'm modding my Retro Tube and wonder what R11 is for,
Please post a schemo when you ask such a question. We don't have all the schematics in teh world.the apex 460 don't have it and the Rode NTV have a 0.22uf cap + 200R resistor there. Is it filtering something?
Where is C11?And why C11 is there and not after cathode? Is there no difference where to place the HF roll of?
C11 acts in conjunction with R11 and the internal impedance of teh tube to produce a roll-off starting at about 10-12kHz. I'm not sure it has much perceptible effect, but it it sounds good to you, it's OK.R11 is between the plate of first stage and grid of the second stage. C11 from R11 to ground. I have increased the value of C11 to 390pf (from cathode of the second stage to ground), and now have better response for speech.
Moving it from where?Is there something I'm missing because of moving it?
Yes, many mfgrs keep the sibilant response because customers are attracted to it when the test the mic. Only to find out later that they would like it less sibilant.Here is the similar Apex 460 (no R11)
This one is very different in many respects. You just can't compare.And the NTV
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