I machine everything myself. I have my own CNC machine that I use for the most complicated parts.

The workmanship on Tim's capsules are amazing. His customer service is outstanding.

The detail that is captured by these capsules are second to none.


I would like to give some insight on the different capsules that have been discussed and some that need to mentioned. Each one has its place and can sound nice in the 460 modded mic.

The capsule that is offered by Dave Thomas is the same capsule that I offer in some of my builds. It has a warm smooth tone and is a great choice for a good sounding 460. The most appealing aspect is the "Bang for the Buck" of this capsule.

The Peluso capsule is a good capsule that has a different frequency response and is also used extensively in these builds. This capsule has more top end than the AA capsule and has more of a "scoop" to the response.

There are three capsules that have not been mentioned here that need to be put into the mix.

The first is offered by ADK custom shop. The GK12 capsule has a great sound that is full and rich. The top end is airy but not fizzy or brittle Great choice for the high end build. They also come in single membrane and a 3 micron 251 style capsule that is mostly for vocals.

Ben at Beez Neez mics also has a new CK12 style capsule that is made "in house" available for these builds. I have not heard these capsules however I have heard the K47 style capsule that he offers and that capsule is outstanding.

Now back to Tim's capsules. These are authentic reproductions of the CK12. The fact that he has the original Gold Mylar shows the length that he goes to, to attain the best sound. I have had them side by side with real CK12 capsules and the frequency response and tone were very close. They were as close as two AKG capsules would be o each other. The consistency of the original AKG builds on the CK12 varied daily. So no two capsules would sound exactly alike.

These are the best of the best for the ultimate build.


Now lets talk about the transformer options.

There are several transformers that are available

The Cinemag is a good sounding transformer that is clean and transparent. This has been the most popular transformer replacement for the 460 mod. The best aspect is you get a great transformer at a good price.

The Chinese BV11 that is offered is best used in the stock cathode follower circuit that is in the 460. The second triode lowers the impendence so that a lower ratio transformer will work.

Tab Funkenwerk has a T11 that has been designed as a drop in replacement for these Alctron mics. I have not heard these transformers, however I have never been disappointed with Oliver's products.

Jensen has their DBE transformer that is a great chioce for this mic. This transformer was used in the MXL 2001 mod by David Royer. This is also the transformer in the Rode Classic mic. Very clear and transparent. This transformer comes "cased" so you must order from Jensen the "un cased" transformer. If you get one with a case you must cut the metal casing off with a Dremel and risk damaging the transformer (not for the feint of heart).

Tab Funkenwerk T14 is my favorite for these builds. This transformer has the most character and warmth. I like it with the Plate Follower circuit because it can be driven harder than in a Cathode Follower. This is a copy of the Hiller transformer that was in the early C12 mics.

Haufe T14/1 is the original transformer used in the C12 and is still available today. I have not heard this transformer in this circuit.

ok, thanks for all of the amazing info guys. now I know exactly what I want... and I just need to save up some funds before I give Tim a call.

cheers
Don

WOW, FANTASTIC INFO! I get the sense that JJ Audio is really aiming to be more of a "custom shop" among the modders.

I've been looking around for information on types of wiring to use, but haven't found much useful information yet. I've gotta rerun a couple wires that are a little too short in one of my 460s. Anyone have thoughts on types of wire?

Thanks for the kind words. Most of my mics are custom pieces.

You should re-wire the entire mic. The best wire to use is the Mil. spec. Teflon coated Silver plated stranded Copper wire.

This guy has short lengths and if you are going to continue modding get several colors.

Use 24AWG for the heater voltage and ground and 26AWG (thinner) for the voltages.

Get rid of the wires on pin 5&6 going to the circuit board and wire the transformer directly to pin 5&6. There is no need to run the signal that far inside the mic.

Don't forget the power supply. Some of the supplies only have 1-2200uf and 2-1000uf capacitors on the heater.

I use 2200-3300uf 35v on the first capacitor and 10,000uf 16v on the second two. Nichicon and Elna's work good here. Bypass these with .1uf MKP2 400v Wimas.
I use the same value (22uf 400v) Panasonic caps also bypassed the same way. Be sure to get the bypass caps in 400v.

Replace the 1uf 400v electrolytic capacitor with a 1uf 250v film capacitor.

I also replace all of the wiring with the Mil spec Teflon. This makes the supply much better and reduces noise.

Hi all,

This is a wicked thread so far. So many variants with these mods! I can and do, get confused

Can anyone tell me straight if:

I change just the transformer (to a 2480 for instance) and the tube to a 6072a, but keep the capsule and caps for now; am I goin to blow anything up? Or make the mic sound terrible?

I do intend to change the capsule and caps, just waiting on funds.

Oh and if anyone is a UK resident, can you tell me where I could get a BV11 tranny? Dave Thomas (AA) seems to be the only resource and I've emailed him a couple of times for a shipping quote, yet no joy.

Many thanks in advance!

Neil

Posted via the Gearslutz iPhone app

You should be able to mod each area one at a time without hurting anything. Each change should alter the sound slightly. Lots of little improvements make the stock vs modded difference more noticable, so results will vary based on what your looking to achieve as well as how trained your ear is.

There is a whole science surrounding how much change is nessesary to make a listener notice.....

Happy moddin !

Tab Funkenwerk has the T11 for the alctron mic and the T49 with the BV11 ratio ( big transformer).

Hiya!

Thanks for your replies guys.

I had a look into that Tab Funkenwerk transformer.

Looks fine, but the price is higher than I was expecting to pay if I'm honest

Comes to about £60 before postage, which compared to about £35 (incl P&P) for a Cinemag or the AA BV11 for £30 (before P&P) does seem somewhat different! I'm sure there are potentially quality differences, but are they THAT different?

Does anyone know of a British maker or supplier of 2480/BV11 style transformers? There surely must be one around?

Sorry to harp on about costs and location of suppliers, but I'm doing this Mod on a budget where possible. Convincing my good lady that money spent in this area is worthwhile is very tricky. Plus times are not exactly flush

Since you are located across the pond, shipping from the USA can eat up good "modding money." Although the VAT also cuts into the bottom line.

Haufe is located in Germany and has the original T14/1 C12 transformer.

Sowter is located in the UK.

Lundahl Is located in Sweden.

All of these are good choices for your project.

Many thanks Jim,

I'll look into those suppliers

I've now completed the entire tutorial; everything was very clear and easy to follow. Again, great job!
Here are my findings:

-removing the cathode follower could be seen as removing low mid mud to some, or remove low mid authority to others, depending on the source being recorded/personal taste (I think I'm going to keep it off)

-It's probably a good idea to do the changes in stages to see what's actually changing to the sound of the mic.

-for C3 and C5, I used Vishay polypro and C6 Nichon Muse (I also changed the capsule with these in one step). I'm not sure what it is, but something here is causing some sort of high end roll off. It's either one of the capacitors mentioned or an something is off with the capsule. I'll know better when Dave Thomas sends me out another capsule. Unfortunately, Canada post is on strike right now...

-I'm also in conversation with Parts Connexion in Canada to see if they can be a goo single source for components, specifically with this upgrade. L&M in Canada sells so many 460 mics, I'm surprised no one has decided to supply parts specifically for this

Once my mics are modded, I will probably look at the power supply thanks to Haz...

If I'm not mistaken the real C12 is a plate follower circuit in the first place. That's the way we do ours along with a few other sweet finds we've made over the years.

The Plate follower to me is more of a tube compression/transformer saturation setup.

The Cathode follower in a good execution like the C37 or the Royer Countryboy mod always struck me as cleaner. I have a Countryboy mic with an Oktava MK319 capsule, Cinemag GINORMOUS output transformer, a huge 3.3uf output coupling cap and it sounds grand in this capacity. Its kind of like my own personal C37, but I call it the Kosmonaut.

Regarding plate follower VS cathode, the classic tube mics of old, the C12, 251, U47 and U67 were all plate followers and have have that classic degree of grab and hold that I always associate with tube mics. To me nothing beats them for that particular application where you need some extra free compression out of the mic.

The lost gain by switching to a plate follower with a T14 is far outweighed by the increase in overall character and action you gain from the microphone.

The T14 by and large is my favorite for this circuit. It also sounds nothing short of incredible if you do the plate follower C12 circuit with a Thiersch M7 and a Tab Funkenwerk T14.

There's quite a few mics out there that have the potential to easily become a C12 or a or a Church 47 with a circuit change, an addition of a good output transformer and a great capsule.

Don't forget the Nady 1050 is a mic ripe for modding! A good deal of whats applied in this thread will work as well in principle. I believe the Nady 1050 comes stock as a 12at7 tube cathode follower circuit.

Peace
Illumination

I would tend to agree with you sound-wise, although some people keep the cathode follower with the CM2480 transformer. It seems to be the one transformer that people pick either option for it.

+1

It dawned on me to double check the polarity on C6 and I made an interesting discovery. If I'm not mistaken, the - or lead marked with a rectangle goes on top and the + is on the bottom. This mic had the original cap backwards! That may explain why it sounded so poor stock compared to my other 460...

seriously????? LoL

that's crappy news, and makes me want to open a few at the local store to check the polarity

I knew it didn't sound great for a 460 when I bought it. I was curious how much effect these mods had on a bad QC mic...

I keep planning to pick up a 460 again and will definitely check that the stock circuit is actually correct before I start my mods.

cheers

Langston,

Don't mean to correct you and Dennis, but the APEX 460 isn't a normal Cathode follower, like the C37. Since the C37 is a pentode wired as a triode and the Apex 460 is a dual triode wired as a constant current draw amplifier.

Brian Fox has talked about it several times on gearslutz. I'm super tired to I won't say much, but Brian made this cool article about this on his website.

The Constant Current Draw Amplifier

This is really cool info and this quote here is classic...
"We have been informed by David Bock of Bock Audio that this amplifier configuration was in fact used in 1995 in the Soundelux U95 microphone that he designed and what's more, it was used before that by a German manufacturer (name unknown at this time) in the 1930s. Thanks to David Bock for helping us keep the facts straight."

Enjoy the read fellow gearslutz!

Min

p.s. I like plate follower mics more too, but haven't used many CCDA and Cathode follower tube mics.

p.s.s. What does cathode biased mean?

...brother min...just pointing out, I made no reference to the C37, nor do I know anything much about that mic to begin with (but I will read your referenced link, thank you)...I simply posted my support for Langston's preference regarding simple plate-follower circuits, as opposed to cathode-follower designs...no need for correction...

PS...both of my Advanced Audio tube mics (CM-47 and CM-12) incorporate cathode-follower circuits, and while both mics sound quite good (Dave Thomas has done a great job with these mics), my other plate-follower type tube mics (like the Stellar CM-6, and cathode-biased Rode Classic I) have a clearer, more detailed and airy top-end which I prefer for most vocalists...

An answer for the "What is cathode bias" is difficult to say in words.

First: What is tube bias? A triode tube like the kind we find in tube mics is actually better thought of as a valve. In fact that's the British word for them.

So this valve can be open, allowing the maximum current it can pass to go through it or it can turned off where the minimum current goes through it. To control if the valve is open or closed you put a voltage on the control grid element of the tube. An audio valve (tube) circuit that is to be low distortion or linear as an engineer would call it needs to be set to a nominal current flow, that sets a kind of middle amount of current flowing. Think of it as an "idle" amount if that helps, like an gas engine has an idling speed.

This allows the signal going into the tube to pull more current through the tube or less current through the tube in a way that is an exact "analog" of the signal. Ahh... an analog circuit is born.

To set the "idle" current all you need is for the control grid of the tube to be MORE negative than the cathode (the part inside that shoots the electrons off of itself) In other words put a little negative voltage on the control grid.

Cathode Bias: So to make cathode bias all you need to do is put a resistor between the ground and the cathode. When current flows through the tube it goes through the resistor too and that causes a voltage drop across the resistor. If the control grid is connected to ground via a resistor as it normally is and the cathode is say 2 volts above ground (positive) then by definition the grid is 2 volts more negative compared to the cathode. Voila! Cathode bias.

It is also customary to put a capacitor in parallel with that cathode resistor but the reasons for that will take me way to long to explain here :-)

Hope that helps.

Brian Fox

This is great! It's funny to read some message boards that say you need to "fix" the mic by removing the CCDA, some simple say it "should" be that way to be more like a C12, and some say "don't!!! I just lost a bunch of low end!". The truth about making the choice to keep or remove the CCDA is closer to picking barbeque sauce for your steak. If you don't like the taste, try the other one.

Also there is a great article of transformers on the Brian's site:
http://www.foxaudioresearch.ca/transformers1.htm

The high end roll off is interesting... ...I may have done that with one mod but not the other...

oh this is such a beautiful description. Very very well done sir. It makes me feel all gooey inside like I did back in high school electronics classes when studying this stuff. I'm in love with electronics. erm.., don't tell my wife....

oh, by the way, I did it - I broke down and bought a used 460 from my new local music buddy Paul Garay.

I have to say, after not touching stock 460s for years, I'm sad that it sounds even worse than I remember mine sounding stock so long ago LoL.

First thing to do is track something with it over the weekend so I can get a "before" sound. I don't know what I'll track or play, I know it won't be scientific because I just don't care enough. I'll probably grab a guitar and strum a few chords, maybe talk into it. if I can I'll put it in front of a monitor (with careful signal routing!) and record some frequency sweeps to get an idea of response.

then it's off to the races with the cheapo mods (ripping out parts that aren't needed) and trying to add in a first order low pass filter in the upper midrange area to see if I can tame this beast down somewhat.

I also forgot just how poor a reach these things have... in other words, it has such a wide cardoid pattern that you have to get up pretty close to it to get any sort of presence at all, otherwise it's quiet and lifeless sounding. I wonder if that's partially the headbasket design.....

I won't be happy until it kicks butt as a vocal mic or becomes a doorstop. hopefully the former.

cheers
Don

My Mil. spec. wire came in the mail today and I started rewiring one of the mics. Unfortunately, I busted the lead on my favorite polystyrene gate cap (1000pf 630v). To make matters worse, the store I got them from no longer stocks them and I can't find them anywhere else! I have another cap that is close (1000pf 50v). Is this enough voltage? I could also order in the 160v to 230v range 900pf and 1200pf. Does anyone know the effect of voltage and pf to the sound?

The voltage from the PS to the tube is about 200v, so i think youd want to use at least a 200-250v cap there. If you have trouble finding something suitable your welcome to have one of the Munfords i ended up not using, just pm me.

Sorry, I meant the C4 Cap - my mistake. I think you had recommended a 160v there. I have a 50v one here, but I'm not sure if that's enough.

No I should have seen you said polystyrene... my bad. I think the voltage listed there is just common for the kind of cap that was in there..you certainly wouldn't need MORE than 200v... I just looked at what I used and its a 160V 1000pf. I have one left and again, yours if you need one... I've got 2 new projects that are non-mic so I wont need another one of these for a while.

Speaking from experience if you apply to much voltage to a cap it goes "pop" .. and depending on what the cap is made out of, can be messy, or occasionally toxic as well. Big electrolytics can be quite dangerous in this regard. Better safe than sorry if your not sure.

Mark

I've replaced all the wiring on one of my 460's with 24awg mil spec from that guy on ebay. I can't believe how much more volume I get from different wiring! I've noticed however that the "grainy sound" is back worse than ever! I didn't use flux - would that cause a problem or might it be one of the caps I swapped out?