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intaud

Tin Man

Posts: 11 Member Since: 13/02/2014

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Feb 13 14 5:31 PM

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I tried this on another forum and received zero response, so I thought I would give it a shot here.

I have developed and prototyped a mic preamp designed to match well with ribbon mics. I’m looking for opinion’s regarding the viability of another dedicated ribbon mic preamp, as a niche product in the market.

There are other very fine preamps dedicated to ribbon mics such as the AEA Trp. I’m offering an alternative that also has 2-channels in a 1u rack mount case, internal power supply (with on/off switch), and 24-position switched gain control.

My main design goals were the following:
- Very low noise and distortion.
- High-gain (80db), high-input impedance.
- No phantom power and its associated circuitry.
- High slew rate and wide frequency response.
- High-quality power supply (I feel this is very important in a quality preamp.)
- Completely balanced and no electrolytic capacitors in a minimal signal path.
- High-quality components and build.
- Estimated sell price: $1,200 for two channels.

I have built several prototypes and tested them at local/regional studios with very good results. My next step involves building several beta units to be used for trial periods at various studios. If beta trials are successful, I’d move to a final production build.

I’m seeking opinions to help me decide whether to continue this effort. Does anyone think there’s a market for another dedicated ribbon mic preamp? I would appreciate any feedback.

Thanks!
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scullyfan

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Posts: 1,543 Member Since:27/07/2011

#1 [url]

Feb 13 14 7:00 PM

Hello intaud

I used to use the preamps on the mixing desk (wherever I happened to be) for my old RCA ribbons and never had a problem with too much noise or too little sound. A few years ago I purchased a very expensive outboard pre designed especially for ribbons. It had very high input impedance, high slewing rate and wide bandwidth (something like 10-500KHz). It didn't suck, but it didn't sound appreciably better than the pres in any of the boards I was using at the time. The only thing I like about the outboard unit is that I can take it into the studio (when I'm recording by myself) and adjust the level exactly where I want it without going back and forth between rooms.

Is there room for another competitor in the existing market? I have no idea, but I personally haven't found any advantages using a pre "dedicated to ribbon mics" over other less expensive options.

Probably not what you wanted to read...

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natenajar

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Posts: 830 Member Since:14/04/2011

#3 [url]

Feb 13 14 11:35 PM

the big advantage to using an AEA rpq is that I can close mic with a 44bx and tame the huge proximity effect at the source. Otherwise, like the other guys said, a good preamp is fine. I've made a good number of records on an mci528 with rca 77's and 44's and it's always been just fine.

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fourloudbarks

Silverado

Posts: 118 Member Since:17/11/2012

#4 [url]

Feb 14 14 8:52 AM

Low noise, low distortion, together with high gain in my opinion is something for which a market exists, but in your case the question is how much competition already exists.   I use non-active ribbon mics on acoustic guitars, and classical guitars a lot.  I have used them mostly thru a TRUE Precision 8, and always wish for more clean and quiet gain.  

However, at this point in my business I hesitate to buy "limited purpose" gear.  I would rather spend extra on a preamp that was suitable for non-active ribbons on such sources as classical guitars because of its low noise and low distortion thru out its 80db of gain, instead of its lack of phantom power.   Otherwise I have to spend even more so I can buy another low noise and low distortion preamp for my mics that require phantom.   Perhaps my problem is is that I don't know how much noise and distortion a bypassed phantom circuit adds?

 

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intaud

Tin Man

Posts: 11 Member Since:13/02/2014

#6 [url]

Feb 14 14 10:07 PM

Thank-you everyone for the feedback! Several good points were made. I recognize any good quality preamp would have sufficient gain and noise performance for louder sources used in rock or pop with a ribbon mic. I think higher gain and low noise is more important for softer sources, i.e. used in classical music.

I don't know how much noise and distortion phantom power would add. I do think it would be worth my time to run a simulation with phantom power added to the design. Then I can compare EIN, distortion, common mode error, etc. If the difference isn't too significant then as podgorny said "why not just add phantom". I will report back my findings.

Of course all this may be a moot point if Steven Slate is right.

Thanks again.

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minister

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Posts: 572 Member Since:27/01/2011

#7 [url]

Feb 17 14 2:58 AM

compasspnt wrote:
I've never had a problem using a "regular" preamp for any ribbons.

But Internet lore seems to dictate otherwise at times.

Yeah.

I have several ribbons here, Royer 122, and AEA A440 (the active 44 design).  Been using a John Hardy Jensen Twin Servo for years.  A dealer INSISTED I try the AEA Mic pre especially designed for ribbons.  It certainly was quite good.  But to my ear, no better than the John Hardy.  And, yes, I did a side-by-side comparison.  Same mic, same position, same sound.  Both sounded good.  Returned the AEA pre.

 

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hallams

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Posts: 1,585 Member Since:26/01/2011

#8 [url]

Feb 17 14 6:50 AM

"New Ribbon Mic Preamp, feedback wanted ........"
I don't understand what all the fuss is about. Just place the mic a bit closer to the speaker, gain up the monitor path and then and wind up the gain on your preamp till it takes off. I must say I prefer feedback via my little valve guitar amp and strat rather than my ribbon mics.

Hallamsound Productions.

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soundaudiotechnologies

New Forum Friend

Posts: 9 Member Since:04/09/2013

#9 [url]

Feb 19 14 8:37 PM

If you want to make inroads for a "new" ribbon pre, you might want to look at valves.

There are plentiful and modestly priced valves that with the right topology, MIGHT be worth designing something around.

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soapfoot

Ruby Baby

Posts: 7,050 Member Since:04/02/2011

#10 [url]

Feb 20 14 9:22 AM

soundaudiotechnologies wrote:
If you want to make inroads for a "new" ribbon pre, you might want to look at valves.

There are plentiful and modestly priced valves that with the right topology, MIGHT be worth designing something around.

That's true. For one thing to throw into the ring-- the RCA OP-6 is expensive, rare, old, and very favored for many ribbons. Originals can kiss $3k per channel at times, so there is demand. It also has some room for 'modernization' if that's your thing. A modern "updated" OP-6 (or even a straight clone/copy) could perhaps very realistically find an audience.


brad allen williams

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ccash

Platinum Blonde

Posts: 1,467 Member Since:19/01/2011

#11 [url]

Feb 20 14 11:41 AM

4038,M130/160, Beesneez Judas and a few other cheapo Chinese ribbon mics sound great on my API 3124.
Just saying.

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hank alrich

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Posts: 1,732 Member Since:28/01/2011

#12 [url]

Feb 20 14 2:02 PM

ccash wrote:
4038,M130/160, Beesneez Judas and a few other cheapo Chinese ribbon mics sound great on my API 3124.
Just saying.

Bingo. And that's what one is up against if one wants to bring something new to the ribbon mic preamp table. API, Great River, Neve, Boulder, Jensen, Hardy, and other good preamps already sit well at that table in my own experience, mostly with various Beyer ribbons, M160's, M500's, M260's, M360. The tube thought might be a window to differentiation here.

hank alrich
http://hankandshaidrimusic.com/
http://www.youtube.com/walkinaymusic

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soapfoot

Ruby Baby

Posts: 7,050 Member Since:04/02/2011

#13 [url]

Feb 20 14 2:05 PM

Right. And being that AEA already has a head-start on the "clean, solid-state, high input Z, specialized ribbon preamp" thing, differentiation might be good.

brad allen williams

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intaud

Tin Man

Posts: 11 Member Since:13/02/2014

#14 [url]

Feb 21 14 7:07 AM

The tube idea is interesting. F.W. Fearn makes tube preamps and one with higher gain marketed towards ribbon mics. I did a little online research and found two people who designed and built OP-6 "clone" prototypes but have not appeared to do anything else with it. It seems there is demand for "clone" type products from the past such as the RCA OP-6, and the design could be modernized with better power supplies and components.

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soundaudiotechnologies

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Posts: 9 Member Since:04/09/2013

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Mar 5 14 6:43 PM

Bringing to market access to rare and desirable tube gear at an affordable price is certainly something that will have some interest.

Have a look at the number of REDD-47 pre amps that have been built from the Drip Electronics product line.

An OP-6 would certainly be a worthy addition to the market, and if the circuit could be optimized to fit into a four space rack as a two channel pre, or even smaller (although I don't see how) it would be even more tempting.

More importantly though... Just when will you have these ready? 

 

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soapfoot

Ruby Baby

Posts: 7,050 Member Since:04/02/2011

#16 [url]

Mar 6 14 8:51 AM

soundaudiotechnologies wrote:
 Have a look at the number of REDD-47 pre amps that have been built from the Drip Electronics product line.

I've personally built ten, so, quoted for truth!

brad allen williams

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marik

Silverado

Posts: 113 Member Since:06/02/2011

#17 [url]

Sep 16 14 12:15 PM

>high-input impedance.

Why? Many well designed ribbon microphones are optimized for a "regular" input impedance, which along with acoustical damping provides electronic one. Both are needed for shaping a flat frequency response and are part of the design...

>Why not just add phantom and call it a clean mic pre with 80dB of gain?

It adds noise. Not crucial with much higher gain condenser microphones, but when we want to squeeze out the last dB of the noise performance at 80dB of gain, noise of the phantom circuit should be considered.

Best, M

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intaud

Tin Man

Posts: 11 Member Since:13/02/2014

#18 [url]

Sep 17 14 6:30 AM

Hello Marik,

Thank-you for chiming in.  Although I have not personally tried one of your microphones (yet), everything I’ve read about them is outstanding.

I guess “high input impedance” is relative.  I selected input impedance based on maximizing voltage transfer and S/N, and reduced loading.  Using simulation I found after about 10k the law of diminishing returns prevailed.  With a source impedance of 250 ohms, and using the 10x “regular” (?) input impedance, the S/N for 2.5k ohms was about 1 dB worse than 10K ohms. 

If you are saying high input impedance can have an adverse effect on the microphone’s frequency response then I need to better understand this.  How does 10k (or 30k) change the curve compared to the optimal input impedance (whatever that is)? 

I’m very interested in the optimal preamp input impedance from the perspective of the ribbon microphone designer.  Perhaps you could offer more input based on your designs.

Thanks, Dave

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marik

Silverado

Posts: 113 Member Since:06/02/2011

#19 [url]

Oct 1 14 12:50 PM

Hello Dave,

Just spent half an hour for a reply and it disappeared... I will try later when time permits. Sorry...

Best, M

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intaud

Tin Man

Posts: 11 Member Since:13/02/2014

#20 [url]

Oct 3 14 4:49 PM

Hi Marik,

Sorry to hear your reply disappeared! It has happened to me too, very frustrating. I definitely look forward to your reply (if you can find the time to give it another go). It sounds like it will be very thorough.

Thanks for taking the time!

Dave

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