Ideas for "Vox Box" type machine (LA-2a based)

[kiira]

Hi! Wow gotta say this place rawks for diy info!

I was just thinking about this and was hoping to get some opinions.

No, not a Manley clone (I'm not worthy! :razz... just based on the idea of having a cool mic/comp/eq machine taylored for vocals somewhat and which can be used nicely with my main vocal mic which is a Beyer M260 with Stephen Sank's DX77 ribbon. None of my current pres really have quite enough gain for this mic, a Langevin DVC and my own tube pre. It needs maybe 65-70db to be happiest I think.

Anyway, when I get these two Telefunken V672s set up (won two PowerOne .5A 24V. supplies yesterday for 25$ woo!) I was planning on building my LA-2a clone.... I have almost enough parts for two of them actually including an A-10 and an HA-100X. I buy all my metalwork at hamfests coz that is the hardest part of audio DIY for me, making the cases and holes and all. I'm getting better at it but like yanno, I want to learn how to do it myself. So I have this HUGE 3U case and it's nice, really high quality with nifty platforms inside for mounting boards and xformers on etc. but it's way too big for just an LA-2a, though it could be made into two smaller cases easily, it's like 20" deep. I was thinking I would like a preamp better suited to my Beyer, why not put it all in this case with the LA-2a clone and heck, add some EQ? Pultec yo.

so... here is what I was thinking

make mic/comp/eq individually patchable acourse

which pre? I dunno this is hard but it needs lotsa gain and can't be too expensive so I was considering the JLM twin 990 design. I would build a tube pre but I don't know of one that does 70db clean gain... I am more familiar with tubes but I can build a SS kit no prob. If I knew how much gain it had I would consider Paul Stamler's design published in AudioXpress bceause I have piles of high class 6sn7s around and I'm sure it is a very clean amp.

Which EQ? I have no outboard EQ at all so the Gyraf Pultec clone is a needed project. It would fit inside the box but I wouldn't have the panel space for all the knobs - I don't think so anyway. What I was thinking is like maybe a simpler EQ suitable for voice eq? sumpin?

acourse I would just build this in stages, La2 first, then the pre. Any thoughts, suggestions, offensive Finnish jokes? But if anyone has any other cool ideas I would love to hear them. I've built some nice stuff and could handle an advanced project like this now I think.

Kiira
http://www.2tough.com/~kiira/rec - me me me

 

[Scenaria]

IMHO I think building an all in one like a voxbox is rather limiting.. considering that for the most part all you save on is some metal work and if your real lucky some power supply...

it'll be easier to mix and match various pre's eq's and comp's by keeping them all sepparate. (if you use one supply then when/if it goes down you lose everything in the box)

that being said...

I personaly am not a big fan of tube into tube... meaning I tend not to run a tube mic into a tube pre.. or a tube pre into a tube eq.. thats not to say it doesnt work... but I tend to find mixing different textures together between various architectures gives a much more interesting sound.

IE: perhaps a G9 preamp into a 1176 compressor.. fed into a calrec eq...

there is such a thing as too much tube :green:

 

[soundguy]

yes, but those recordings, the ones which I think sound best, didnt use any transistor technology and I think that is the point, where you start introducing the up front sound of transistors where too much tube can be too much tube. If your signal path down to the tape machine is %100 tube, you dont have ay spatial perception to deal with, everything is tube. combining solid state and tube is where things can become a mess.

dave

 

[kiira]

[quote author="kubi"]
Do you want to buy a kit and assemble it or do you want to build from scratch?
G9? Good sounding and very easy to build due to all the information we collected here. Go for P2P if you need one channel only.
Hamptone? JFET or Tube, both are good sounding, well documented and easy to build.[/quote]

I can build, and even design some, tube stuff from scratch but not SS. I only know about tubes so I was thinking a kit. I need lotsa gain for the ribbon. The JLM99v looks cool!

Pultec is alright even if you don't have the space for the knobs, because do you really need all bands of a pultec PEQ1A? Maybe a MEQ5 is more suitable for vocals? Or just take the bands from these both EQs that you need and skip the other bands to save space (and parts and costs).

What is a MEQ5? Is there a page about it somewhere? I like hand holding when I am building things.

 

[kiira]

[quote author="Scenaria"]IMHO I think building an all in one like a voxbox is rather limiting.. considering that for the most part all you save on is some metal work and if your real lucky some power supply...
[\quote]

and some rack space. but yeah I see your point. It's just i have this huge case. whatever.

I personaly am not a big fan of tube into tube... meaning I tend not to run a tube mic into a tube pre.. or a tube pre into a tube eq.. thats not to say it doesnt work... but I tend to find mixing different textures together between various architectures gives a much more interesting sound.

IE: perhaps a G9 preamp into a 1176 compressor.. fed into a calrec eq...

there is such a thing as too much tube :green:

I'm hip. Though it's acourse possible to build very clean neutral tube equipment my idea was to use a SS pre. I was thinking the Twin Servo 990 but this JLM990v kit looks really interesting and has good high gain for my ribbon. I don't want to buld an 1176 because I have all the parts for two LA-2s already.

I was just thinking a voxbox type project would be fun and interesting but yanno it really doesn't make all that much sense for a diy project. I would like the full Pultec clone EQ anyway.

thanks!

Kiira - girl with a soldering iron

 

[soundguy]

hey kira-

your cat is excellent, have you considered modifying him at all?

If you are considering building the JLM 99v kit, its way easy to put together and understand and it sounds frighteningly good, certainly as good or in most cases better than any commercial product you can go and buy.

dave

 

[Kev]

Rather than pointing Kiira to other links and existing projects which I'm sure she knows about. And I'd like to point out that we have her circuit at the bottom of one of the Group DIY web pages ...

I think we should encourage Kiira to do some thing from scratch and add a new project to our list.

Kiira,
I simply have no time BUT if you want some assistance or just want an ear to bounce ideas of then I will always make time. I can channel you to other people if you like ... don't be shy ... just do it.

It all started one day in 1999. I thought to myself... "gee, Kiira you are a musician and a nerd girl too -

we simply need more of you in our industry
you know were I am
:thumb:

 

[Michael Krusch]

I had planned the same thing as you, but came to the conclusion to build each funktion into a single box, because it's more flexible and I'm the record-now-and-process-later guy.
I designed that layout, I hope it will give oyu some inspiration.

http://www.digital-synthologie.de/altec_preamp/images/voice_channel.gif

If you really want something similare to a Voxbox, you will need a preamp, a LA-2A optical compressor, a Pultec MEQ5 eq and a 1176 Fet compressor with switchable filter in the sidechain.

 

[kiira]

[quote author="Kev"]Rather than pointing Kiira to other links and existing projects which I'm sure she knows about. And I'd like to point out that we have her circuit at the bottom of one of the Group DIY web pages ...

I think we should encourage Kiira to do some thing from scratch and add a new project to our list.
[/quote]

OMG thanks for the encouragement Kevin and all but I don't know if I'm there yet. :roll: Well, there is one project I've been wanting to do - a clean high gain pre that can have its character altered... like a pre version of a distressor except without the digital stuff of course. I have a lot of nice octal tubes I could use and add a gain stage that could be bypassed. Like most of the studio pres around use miniature 9 pins like 12ax7, 6072, 6dj8 etc. I'd like to try something different.

Kiira,
I simply have no time BUT if you want some assistance or just want an ear to bounce ideas of then I will always make time. I can channel you to other people if you like ... don't be shy ... just do it.

you rock.

Kiira

 

[kiira]

[quote author="Michael Krusch"]I had planned the same thing as you, but came to the conclusion to build each funktion into a single box, because it's more flexible and I'm the record-now-and-process-later guy.
I designed that layout, I hope it will give oyu some inspiration.
[/quote]

ding ding ding... that is exactly what I was thinking of! I think I will prolly just do the same thing though and build seperate projects, though it might be cool to put a mic pre into the LA-2a. I have the parts for two so if I really want one later I can build it and building the PEQ1 will give me some insight into the EQ I would want to include.

thank!

Kiira

 

[kiira]

[quote author="soundguy"]hey kira-

your cat is excellent, have you considered modifying him at all?
[/quote]

Have you ever tried modifying a cat? It's a big project and what do you get when it's all done? Besides, he told me he was perfect as he is and I tend o believe him. :roll:

If you are considering building the JLM 99v kit, its way easy to put together and understand and it sounds frighteningly good, certainly as good or in most cases better than any commercial product you can go and buy.

dave

cool cool. I was reading in the archives and yes, it sounds like what I need for my Beyer ribbon! I just need a good high gain pre for that... the Langevin has like 50db and my old Tascam console has 60 but it still needs a little more to shine I think. Things get slightly noisy when I crank up the output yanno. High output condensors sound great thru my own tube pre and the Langevin DVC but so far the M260-DX77 is the best mic for my voice I've used other than the expensive Neumans in studios I used before I knew anything about equipment or engineering.

tra!

Kiira

 

[Bear]

Kiira, still working the CMC-16, I see. :thumb: Yours seems to be the white whale, as I've seen plenty of 32's and 24's, but only your one 16. I'm not even sure A&H knows they made those. I assume you're beyond the useful gain range of those pre's, which I was recently surprised by them for how good they sound.

For gain for a ribbon mic, the JLM boards are a good and ready solution, and you don't have to mess w/ etching or anything. There are some good prior threads to checkout for info, especially regarding the question to servo or not to servo. Instead of Joe's opamps, you might try the JH990 or FT992/993 for a cleaner, more "wire-with-gain" sound.

Bear

 

[kiira]

[quote author="Bear"]Kiira, still working the CMC-16, I see. :thumb: Yours seems to be the white whale, as I've seen plenty of 32's and 24's, but only your one 16. I'm not even sure A&H knows they made those. I assume you're beyond the useful gain range of those pre's, which I was recently surprised by them for how good they sound.[/quote]

OMG! I've gotta put it on ebay! "Rare priceless vintage relic, only one made for obscure Finnish chick headbanger!" BIN $1200

hiya Bear! No I just recently retired the CMC-16. That is my very old web pages which I have not redone... I have a new studio which is now adining room studio not a bedroom studio.

I was mad at the A&H because the busses and the CARS started acting flakey and I needed a bigger mixer anyway. I got a tremendous deal on a minty Tascam M512, which I am wiring in today. I really do wish that the CMC-16 was modular because I would rack the pres... they are really pretty darn nice! It's the board all together I don't like too much any more. I am going to open it up and service it and then decide what to do with it. It might be handy as a monitor console or something.

For gain for a ribbon mic, the JLM boards are a good and ready solution, and you don't have to mess w/ etching or anything. There are some good prior threads to checkout for info, especially regarding the question to servo or not to servo. Instead of Joe's opamps, you might try the JH990 or FT992/993 for a cleaner, more "wire-with-gain" sound.

That's the plan then. I was also thinking to have the jh990 chip to swap out... socket them and socket the input xformers and get different characters. It would be pretty dramatic between say my old very colored Newcombs (thing they came out of a Grommes mixer) and the clean Jensens. woot.

Kiira - thinks it's official, this is my favorite music stuff forum... along with homerecording.com.

 

[Michael Krusch]

[quote author="kiira"]
ding ding ding... that is exactly what I was thinking of! I think I will prolly just do the same thing though and build seperate projects, though it might be cool to put a mic pre into the LA-2a. I have the parts for two so if I really want one later I can build it and building the PEQ1 will give me some insight into the EQ I would want to include.

thank!

Kiira[/quote]
I had good results putting a mic transformer in front of an 1176 and using a TLM103, it would work if you do the same with the LA-2A. But you have to add phantom power also.
Most of the time I only use the high boost part of the Pultec for vocals. Maybe it's also enough for you. Would not be so complicated to put this inside one box.

 

[kiira]

[quote author="Michael Krusch"]
I had good results putting a mic transformer in front of an 1176 and using a TLM103, it would work if you do the same with the LA-2A. But you have to add phantom power also.
Most of the time I only use the high boost part of the Pultec for vocals. Maybe it's also enough for you. Would not be so complicated to put this inside one box.[/quote]

I can't do that though because the mic I'm building this stuff for is a low output ribbon. That's the whole thing.. I need 70db of gain. A tlm103 puts out a lot of signal!

Kiira

 

[JLM Audio]

You can insert a Pultec passive EQ type circuit (without make up amp) straight into the Dual 99v Mic Pre where R18 is. Or a opto comp circuit can attach to this point by making R18 about 47k. I have been thinking about making a small PCB that has the comp parts on it mounted to the threshold pot. Would only need power and one wire to the +in of the second 99v to work.

Just a thought

Joe :grin:

 

[kiira]

[quote author="JLM Audio"]You can insert a Pultec passive EQ type circuit (without make up amp) straight into the Dual 99v Mic Pre where R18 is. Or a opto comp circuit can attach to this point by making R18 about 47k. I have been thinking about making a small PCB that has the comp parts on it mounted to the threshold pot. Would only need power and one wire to the +in of the second 99v to work.
[/quote]

Hi Joe, thanks for the info. I would be interested in something like that. My only thing is that I would want to have the EQ after the compression.

I just discovered my "new" mixer is fubarred yesterday so my new projects will have to wait until (if) I can fix it. foo!

I have pretty much decided I would really like the jlm99v though. How much gain does it have? What do you think of my swapping input Xformers/Op amps idea? Cool?

Kiira

 

[CJ]

Just a note on the MEQ-5, the major difference between it and the EQP-1A is that there is only 10 db of tweaking, instead of the 16-18db of the EQP-1A, and the midrange bands cut instead of boost frequencies. The EQP-1A boosts the inductor basded frequencies.
Also, the bass and treble circuits use inductors, whereas the EQP-1A only uses one inductor for the treble boost.
cj

 

[Swedish Chef]

If the case is so big and you really want to use it, you could build them all in there and have discreet i/o which you could then patch either via connectors or if you have a patchbay then on t'patchbay. That would be pretty flexible, but might get heavy in a hurry!
Oh and I can't recommend the JLM mic pre enough!
Just buy one!
Just ask Poodle-Cat-Dave... :green:

chef

 

[CJ]

Even with a remote pwr supply, I had a time getting all the EQP-1A stuff in a 1U box, but I used a lot of relays. If you wanted a MEQ and 1A in the same box, it would probably have to be a 2U rack job.
The Tremaine book recomends at least 100 volt caps for the passive section, which can get pretty big, especially the 1 uf and up stuff.
:guinness: