Cascade Elroy Mod's?

Well, So I have one of these Cascade Elroy mic's and I've caught the Mic Modding Bug. Dangerous to my pocket book, but hopefully it'll yield some good results like I was able to get from modding a pair of MK-012's recently. Anyhow, the mic suffers from a lot of the weak low's, over hyped highs, and lackluster mids that are typical to a lot of these chinese tube mic's, so it would be nice to see if theres any changes I can make to this mic to make it a useable tool for doing rock vocals and front of kick duties. I'm doing another project of the C12 nature based off an aphex 460 platform, so I would like something of another flavor. M49ish maybe? I'm thinking mild to wild. Capsule? Transformer? Tube? Caps? I've seen that advanced audio does a mod to this mic with a 6072A Tube, Peluso CEK-367 Capsule, and "Circut Changes" so I'm curious what those changes are. Any help/thoughts you guys can throw my way would be great to hear!

I found this on the AMI site, http://www.tab-funkenwerk.com/id89.html And it seems to contain most of the schematic information for the M49, and lists that a AMI BV11a would be a proper transformer for the job, or maybe a T14. Tube should be an AC701(K) and capsule should be an M7 type. Would any of this work with changes to the preamp board and power supply?

These are the documents for the Trion 8000, should nearly be the same mic as what I have. Thanks to Mista Min for posting these.

http://dl.dropbox.com/u/13352325/DIY/TRION%208000%20SCHEMATIC.pdf
http://dl.dropbox.com/u/13352325/DIY/PS120-SCHEMATIC.pdf
http://dl.dropbox.com/u/13352325/DIY/TRION_8000_spec.pmd.pdf

Did you ever complete a mod on this mic?

You want to mod it?
Check is the schematic (above) for CAD is the same (probably yes), check output capacitor connection - looks strange and there's no problem to mod it. I can help you.

Hey Man,

Yeah, I would love to mod it… I started another thread related to the capsule.

So I looked at the schematic and it looks similar, though I don't see the switches for roll off or pad. I'm really new to this and haven't read schematics in 10 - 15  years and even then I was no expert.

Would it help if I get some good photos of the guts? Anything I should focus on that would help you evaluate the situation?

Thanks

Hey!

Yes, good photos of guts would be really great option for starting mod
Especially you could make photos of switches connections (except polar pattern) so we could add it to the schematic.
Here's first step of mod in attachement.
I recommend to make mod with adjusting some parts of the circuit during the voice test and some basic measurements.
Do you have multimeter?

Update:
For start, as i said, i would stay with original capsule. This mod is for flat circuit but after we check the circuit with the photos i will make some update for high frequency filtering. Do you need HPF? Maybe there would be better to make LPF switchable filtering? Three position for example?

For now, as you can see, there's nothing unusual here. No electrolytic cap inside microphone and few minor changes.
I think that you should change the tube in the first place. From my experience, these chinese 6J1 sucks.
If you will had to order parts, give us know first, i will give you few tips, what and where will be good
I would keep original transformer, at least for now. I'll try to find some info what's ratio of it.
Schematic Update 1 - V1

I have info from Khron, that transformer is probably 10:1, what would be typical for most of chinese tube mikes.

Ok, here is a link to more photos and a video of the inside of the mic. I hope these links work for you guys. I think its easier than replying several times to attach multiple photos.

https://www.dropbox.com/sh/mhyrcf5oyl98msv/AABzzv-JKw5Nnexi7arFb9sqa?dl=0

1. I do have a multi-meter.
2. I'm fine waiting on the capsule for now while we get the electronics working but I'm sure I'll want to do that at some point.
3. I fine sticking with a HPF but I'm open to hearing if you have some other idea… I think that the high end will be resolved with a RK47 type capsule if I understand right from other reading.
4. Yes a tube upgrade is definitely called for.

Let me know what you see after checking out the photos.

Check PM

Could you describe pad and hpf connections? I tried from the pics but it's hard to see.
Also there is one blue foil cap, can you check the value and where it's connected?
R10 is resitor - is there any potentiometer on the board? I don't see any.
Where is connected R10?
47uF electolytic capacitor - is it C4?
What's the value of small ceramic capacitor at the switch side of PCB?
Is it white wire of transformer connected to ground? It should be
I'll be updating schematic in the post above, to stick with only one version!

I will talk a look later today and attempt to give you more info.

One question… what specifically should I look to describe about the connection of the pad and HPF?

What an where is connected, switch pins and parts, and where these parts are connected
You could check value of ceramic capacitor for PAD and is it correct connection on the schematic.
Still left HPF

This Microphone is going places!
--------------------------------------------
After getting the news that he would be going under the knife (soldering iron) next month, in an attempt to correct some fundamental and potentially terminal ailments, Elroy has decided to go on a road trip across the United States. With worry, fear, and hope on his mind, he set off from Austin, Texas to find purpose and strength to help guide him through his upcoming trials.

We check in with Elroy now after 10+ hours of driving and a stay at the world famous Best Western Plus - Little Rock. Elroy has refueled at the Blues City Cafe, a full rack of Memphis ribs has revitalized his tired soul and he now prepares for a push North.

PS. Circuit info requested will be posted during Elroy's journey.

Lets call it - on the road mod!

micaddict said:

https://www.youtube.com/watch?v=ZYj9J4UH8ck

Click to expand...

Ok so here's new version of schematic V2 - i didn't replaced V1, becuase it's easier to compare changes in circuit.
This one have different input arrangement. For cardioid much more better, than previously.
"a" suffix like C3a is for additional parts.
There would be more gymnastic for eyes, to make connections, but it's possible without any problem.
Definately worth!

Cleaned up the mess on the schematic - now should be better readable.
Give me know if you really want HPF - so i will update schematic.

After leaving Memphis satiated by the local delicacies, the carnivorous Elroy pushes hard to put many miles behind him.

The plan was good, the plan was safe but…
The approach to the city was paved with anticipation, the promise of rest, and the surety of safe harbor but alas, the gates to the city were closed and every in was full. Elroy, weary from the road was forced to press on… Nashville the land of country music was over run and had no comfort to offer on this night.

Still, Elroy liked his chances… supplies were plentiful and his sprits were high. With plenty chicharones and the elixir of Monster in tow, he would surely make it to the land of the slugger… the birthplace of the Greatest boxer to ever live…Louisville.

https://www.youtube.com/watch?v=hPDCzZZ9ecI

Isn't 3.3 uF  // 3.3K a bit low for a good bass response?
(Unless you want to roll-off the LF response intentionally)

RuudNL said:

Isn't 3.3 uF  // 3.3K a bit low for a good bass response?
(Unless you want to roll-off the LF response intentionally)

Click to expand...

It shouldn't be to low, but good that you pointed  out.
I forgot to make description for it

C4 - 3.3uF film capacitor is the value for start (i reccomend here EVOX RIFA MMK cap)
If there would be any  lack of low end i propose to start connecting two in parallel, if still - there would be need to make test with
electrolytic capacitor values. Still i would connect it in parallel to the one 3.3uF. Still start from low values let say 10uF and so.

Why 3.3uF - it's  ripped from my S16 microphone project.
http://groupdiy.com/index.php?topic=62423.msg791063#msg791063

In S16 any higher value gave me boost of low frequency, really unwanted
I designed it for 6028 use but tested it with 5654 and the result was the same.

Anyway - here's matter of test. I would start from 3.3uF and adjust plate resistance with pot.
Also here's is higher cathode resistor than in S16, so there's chance that it will behave similar.
Then we see what happend

Well, Elroy is back home after an epic summer voyage. Now lets look in side and see what we can do.

ln76d said:

Could you describe pad and hpf connections? I tried from the pics but it's hard to see.

Click to expand...

https://www.dropbox.com/s/nwo99nuftcflwu0/Elroy%20Pad_HPF%20Connections.jpg?dl=0

PAD:
1. There is a black wire from the capsule that connects to the pcb. This point connects to one post of R4 on the bottom. On the top it connects to a 1nF film cap.

2. The other lead for the 1nF film cap connects to the PCB at a point that connects to R7 on the bottom. It is jumped over to a point that connects to pin 1 of the tube on the bottom.

3. From pin 1 of the tube there is a ceramic cap (331 pF i think) that connects to the PCB on the top. This point connects to a trace that leads to the middle post of the PAD switch.

HPF:

1. There is a trace that connects to the right pin of the HPF switch. The trace leads back to one of the leads for R11 on the bottom.

2. This same point on the bottom connects to the 22 nF film cap.

3. The other side of R11 is connected by a trace to one lead of R9.

4. That lead of R9 has traces that go to the the positive lead of the 2.2 uF electrolytic cap and the negative lead of the 47 uF electrolytic cap.

5. The 2 red wires coming from the capsule connect to the positive lead of the 2.2 uF electrolytic cap and the negative lead of the 47 uF electrolytic cap from the other side of the pcb board.

ln76d said:

Also there is one blue foil cap, can you check the value and where it's connected?

Click to expand...

https://www.dropbox.com/s/pdcaq8lkqovkzg5/Capacitor%20values%20and%20connections.jpg?dl=0

I believe you are referring to the cap that is R7 and R10.  The value of the electrolytic cap is 1 uF. The negative lead is connects to R10 and the positive lead connects to pin 5 of the Tube as far as I can tell.

In case you are referring to the other blue capacitor, it is 22 uF (223J) and it connects on one lead to R11 and on the other lead to tube pin 5 via trace.

ln76d said:

R10 is resitor - is there any potentiometer on the board? I don't see any.
Where is connected R10?

Click to expand...

https://www.dropbox.com/s/xtzld8la3t95fet/R10%20connections.jpg?dl=0

I do not see any potentiometer. It seems to be connected between the K3 (HPF) swith and the negative lead of the 1 uF electrolytic cap. There are 2 lead from the switch that lead to each side of the R10 resistor.

ln76d said:

47uF electolytic capacitor - is it C4?

Click to expand...

https://www.dropbox.com/s/iq5ooe72rqlxvez/Elroy%2047uF%20connections.jpg?dl=0

I don't see any markings designating which capacitor number for any of the caps. The negative lead of the 47 uF cap connected to one of the red wires from the capsule and one of the lead of R9. The positive lead connects to a trace that leads to R9 and a trace  to Tube pin 7 at the same point.

ln76d said:

What's the value of small ceramic capacitor at the switch side of PCB?

Click to expand...

https://www.dropbox.com/s/g6gwahbxy8ktazy/Tinyasscap.jpg?dl=0

It took me forever to figure this out as the writing was so small and light colored. I finally got a picture of it that I could blow up.
The number on it was 331 but no other markings.  I think this means 331 uF but correct me if I'm wrong. (***I was wrong this is 331 nF... thanks ln76d)

ln76d said:

Is it white wire of transformer connected to ground? It should be

Click to expand...

https://www.dropbox.com/s/7w65lp91re168y4/transformer%20ground.jpg?dl=0

The white wire of the transformer connects to the PCB board. From there, there is a trace that appears to connect to the white wire that connects to the 7 pin output connector.

Wow... ok my brain hurts. Please feel free to correct me or educate along the way.  I'm finding this quite interesting. Thanks in advance.

Also, I found that shining a small light behind the PCB make the traces on the opposite side more visible.  I can take more photos of anything you want to see better. Just let me know.