Looking for schematic for Rode Classic mic

strangeandbouncy · May 25, 2012

HI Guys,

I am looking for the schematic for a Rode CLassic mic. Can anyone help me here? I guess the Classic II might be useful if I cant get the Classic I . . .

kindest regards,

ANdyP

Gus · May 25, 2012

IIRC there was a link to one at this site in the past. I can't seem to find it

What is the issue with the one you have?

strangeandbouncy · May 25, 2012

Hi Gus,

there is a link in another thread, but it is dead, and is also for the Classic II. I don't know how different they are. Issue is this. Owner has had mic for nearly 15 years. It is starting to be a tad lifeless. Tube swap makes no difference, and it measured fine a few months ago. I suspect the diaphragm has lost some tension. He is not a quiet singer, and it has been in daily use! He was asking me about what to buy. He really wants a u47, m49, etc, which always sound stellar with his voice. NO money, and I reckon he will hear a considerable improvement if we replace capsule with a Thiersch pvc or mylar m7. Much cheaper than any re-engineered chines mic. I think classic has 6072 tube. I have a handful of 5 star 6072. We could also replace the output transformer, or do the AMI EF800 mod to it. Any-which-way I look at it, he will be better off!

I was hoping to glance at a schematic just to get the lie of the land, check polarising voltage is not too high for m7 etc etc.

KIndest regards,

ANdyP

Gus · May 25, 2012

First check and test the capsule.
Sing into the back of the capsule in figure 8 make sure to invert the signal. Sing into the front and then the back of the capsule in Omni. How does the microphone sound now? Sometimes you can flip the capsule around and get more life in cardiod it is not 100% because both membranes matter at the lower frequencies.
Look at the capsule and inspect for wrinkles and dirt.

Check the power supply voltage under load. I would guess it is 120VDC B+ and 60VDC capsule and 0 to 120VDC capsule pattern voltages. Check the plate, cathode and heater voltages. Check the plate to transformer output cap IIRC it was a large value electro I thought that was odd, maybe try a mylar, PET 1uf film. Check the cathode bypass cap.

Before you do any changing of parts, measure what you can.

I have NTV and it has a Jensen transformer what does the classic have? if a Jensen I would keep it.

With age I check electrolytic caps often they are good but sometimes they dry out.

I would make sure the circuit is good before I would change the capsule. A M7 or a K47 or a C12 might be fun to try.

strangeandbouncy · May 25, 2012

Hi Gus,

it is not in front of me right now, but of course I'll check it out as you suggested. The other factor to include is that, like the rest of us, the owner is 15 years older too, and his voice has certainly changed! If the capsule is on it's way out, I guess it will be pretty much the same sort of cost to replace as to substitute with m7 or k47. I know from experience that C12, 251, and C12a sound awful with him, whereas every k47 I have tried( u48, Sela T25, my own lash-up with gefell head on KM56 body) have rocked the house. - I think I'll be going the k47 route!

fact is, that even repaired as stock,he wont get enough for it to get anything else . . .

Kindest regards,

ANdyP