Modded Rode classic II

[Audiofreek]

Bump!!

[dave thomas]

Hi, did you in fact verify that the Rode II had a Jensen output transformer?

The original Rode Classic had a Jensen output transformer but when you check the spec of the Classic II from the Rode site it states bi-polar transistor transformerless balanced output stage.

I suspect that the Rode Classic II Limited Edition had the Transformer but the Classic II did not.

So, it is possible someone has removed the Bi-polar output stage and fitted a Lundahl transformer. The power supply would also be different for the Classic II with the tranformerless output compared to the original Classic.

The 5:1 ratio of the Lundahl is to low if the circuit was wired as a single stage C12 type plate output circuit with a 6072a tube.

The original capsule had 5 micron skinned diaphragms and would be brighter in the upper mids as shown by the Rode Specs than our AK12 capsule or the Peluso CEK12 capsule which has an OD of 24mm and is skinned with 6 micron mylar.

If one of the capsules was upgrades with our AK12 or a Peluso then you would certainly be hearing a difference in the capsules???

Cheers, Dave

Originally Posted by Audiofreek

Hi,I'm looking for a schematic for a pair of Classic IIs that have had the custom Jensen trannies replaced with reversed Lundahl 1538 transformers(not sure why?)
It doesn't stop there,one capacitor has been upgraded,a component that looks like it may have been a fet(PCB shows a small half mood shape and three empty holes) has been removed,and one resitor has been lifted at one end.
I didn't pay a ton for these mics cause I knew they had been modded,and waranties were void.I got them from a guy on Kijiji,who had them for a few years after purchasing them from a guy on ebay that does some DIY builds in the Victoria BC area(not sure who it might be).
One of the issues I am having,is the mics sound different from each other,other issues I had were rectified by cleaning cable contacts,and reattaching the lifted resistor(this was causing a pulsing thump in mic 1 when the high pass filter was disengaged,but made mic two sound more open and bright).
Mic one has about a 6dB lower output,but has a more buttery sound that I prefer,Mic two has more midrandge punch,a higher output,but not as pleasing of a sound when tested in cardiod(sounds very similar to My K2).
After having swaped tubes,power supplies,cables,recording samples of my voice testing fronts and backs of the capsules.I've noticed, after cleaning and inspecting the capsules,on mic 1s capsule,the back plates are more easily visible,and more gold is missing from the diaphrams(not flaked off,but worn looking.)Mic 2s capsule looks newer,and in better condition.Could this be the reason for the higher output??
Both capsules are edge terminated,and more or less look to be of the same construction.Should i swap the capsules to see if the output goes up in mic 1?
I taked to Dave a AA Microphones ,and he offered to get the mics to match up as a stereo pair for a very reasonable price,possibly some component and capsule replacement.
The issue here is that I don't really want to put much more money into them,I can't really sell them for what I paid for them($1,400.00 for the pair),because now I am aware of every issue with these mics that I would feel obligated to disclose to the buyer,although some issues have been resolved.
While I do like the sound of the mics,(although they are different,they are still very useable,but some applications are more suited for one over the other)I would still like to resolve the issue at hand,but good luck trying to find a schematic for ANY Rode mics.If some one has a schematic that they would like to share for the Classic,or Classic II,please?just so I can see what has been done.Perhaps a conversion to a U47 like plate following mod has been attempted?
If nothing else,this is a cautionary tale for those fooling around with a perfectly good mic design,and then having to pawn their F.U. off on someone else,and that someone else things they are getting a good deal.

[Haz-Mat-Strat]

The Rode Classic ll that I worked on was also modded with a custom made Lundahl transformer that was on a bread board. and crudely attached to the circuit board.

That mic did indeed have a pcb layout for the Jensen transformer.

I also worked on the Rode Classic that needed a new transformer. The transformer in both mics is the JT-DB-EPC and if you contact Jensen they may have some with the original Rode markings.

The Rode spec sheet shows the Classic ll with the Jensen specs.

[Audiofreek]

Hey thanks guys,I haven't been around here for a while.It is good to know what the correct Jensen transformer would be.Jensen has that Transformer (JT-DB-EPC)listed as a direct box tranny with a 12:1 ratio,where the LL1538 are a 1:5 wired in reverse,interestingly enough they are crudely attached breadboard with a sticky blue material(perhaps one of the same mics).
Although I like the sound of mic 1,my biggest concern is the higher self noise.It would be nice to be able to use these as a matched pair,but I recently used them as pair in a Glynn Johns type set-up on a kit,with a Rode K2 on the kick as well,and it killed.
The odd thing I noticed is that there seemed to be a FET in the circuit that had been removed,and jumpered.

[roginator]

I replaced capsule in mine Classic I ( with KK67) ... only cause i was sick of waiting one year to get new capsule from rode !!!!

IT was crackling and noisy !!

also i replaced tube with GE 6072A 5 star

This mic now rocks!!

here are some schematics if you guys need em !! .. for rode Classic I











hope this helps .. have fun

[Audiofreek]

Thanks so much for the schematic,although it is a different mic,it should be helpfull.

[prairiedog]

roginator,

I've just bought a Rode Classic with an intermittent fault and need schematics. The schematics you posted don't seem to be available any more. Is there any chance you could re-post them, or email them to me if you prefer?

Thanks
Demetris

[thiagomachosky]

Originally Posted by prairiedog

roginator,

I've just bought a Rode Classic with an intermittent fault and need schematics. The schematics you posted don't seem to be available any more. Is there any chance you could re-post them, or email them to me if you prefer?

Thanks
Demetris

Hi,
did you get the schematics?
also need them