Fun looking mic

:slight_smile:

Cascade Ribbon Fathead Mic

Never owned a ribbon mic. I have heard recordings using various ribbon mics and didn’t really like the sound of them. Still, I own quite a few mics and at $300 a pair, might be a GAS investment.

Ribbons need to be stored upright, right?

Yes.

I own a reconditioned 77dx - found it for beer money at a sale, had it reconditioned by Stephen Sank - and I have to say, I have often thought of selling it, since I don’t really get good sounds from it, compared to even something like my new/used Audix OM-5, or the Rode mics I have. I must be totally wrong, and missing something. Or maybe it is this particular mic - it’s really the only ribbon I’ve had experience with. But when I listen to Al Green on the same mic, I think - I must be wrong, I must be missing something…

… like the right pre?

Well, I know that’s probably it, but I’ve tried it through a number of different ones, including the Eureka, which has variable impedence, but…

Anyway, it’s definitely something I want to revisit after our move.

:)

(spooky voice)

"Tom, you will sell your RCA to Clava Studio…sell it Tom…sell it to Clava. Clava needs another ribbon in their locker…

(/spooky voice)

Ribbons have a sound that isn’t easily described. And if all you’ve worked with is modern dynamics and condensors, a ribbon mic could very well leave a person cold. Many sound like they don’t have very good detail, but that’s often a function of the room, the source material, or the preamp (or combinations thereof). In front of a LOUD guitar amp though? Or used as room mics in a good sounding room? Or for intimate but not sibilent vocals (if you have enough gain to drive one well)? I use a ribbon mic on just about every session for a variety of reasons and in a buncha different locations. There are enough affordable options these days that you don’t have to drop the money you used to to try one out, which can only be good.

And seriously Tom…if you decide to unload that 77 I have a nice comfy room for it and a rack of cool amps to plug it into…

Hmm. I will have to think seriously about that, Clava.

What would count as a good preamp for it? You know pretty much what I have. But I’d sure like to know what I’m missing - and whether it’s really of any use to me.

At the risk of being Trollish, I wonder if there’s a general guide that might indicate appropriate preamp/mic compatabilities? It seems I hear a lot of talk about needing the right pre, but it’s a wide-open guessing game.

Thoughts? Flames?

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At the risk of being Trollish, I wonder if there’s a general guide that might indicate appropriate preamp/mic compatabilities? It seems I hear a lot of talk about needing the right pre, but it’s a wide-open guessing game.


I don’t think I’d say “guessing game”, but there is some hit and miss at pairing a mic and preamp sometimes. Lotta folks know that the output impedence of yer typical ribbon mic is less, sometimes far less, than a typical moving coil or condensor mic. This makes certain demands on the input side of a preamp. Back in the day, the input transformers on preamps weren’t the sort of shelf items they are now (for those amps today that have input transformers). They were specially designed and wound for the circuit they were part of…often a circuit that was expected to work with a ribbon mic.
Lotta ribbons also don’t have a very strong output voltage at a particular source SPL, which is why everyone says they need lots of available gain to be useable. Again, used to be that there were several stages of gain applied to the signal before the recording device…mic preamp -> line drive amp -> tape machine input amp…that was standard. Each gain stage may not have been a lot on it’s own, but together the system of amps got signal into a useable range without overloading any one stage. A single modern preamp into a DAW isn’t the same thing.
Signal levels were different too, especially back in the days of low output tape (which roughly coincides with the heyday of ribbon mics like Tom’s RCA…). Even today, you don’t need a high signal level to tape to get a fine recording (or to a DAW either, at least in my book) if you calibrate your machine right for the tape you’re using. Not a lot of tape users here though I bet. Folks new to modern digital recording somtimes try to print signal too hot in an effort to “use all the bits”. This subject, and some of the falacy behind it, has been discussed quite a bit here by those far more in the know on it than me.
Unfortunately, these factors mean that digital recording with modern amplification equipment doesn’t allways work well with 50 year old microphones. A list of which mics work well with which amps would be pretty hard to put together and probably wouldn’t be worth much since the source material has a lot to do with how well a combination works. I wouldn’t put a soft singer in front of an old ribbon into a Langevin preamp (which has limited gain), but I’d put that same combo in front of an AC30 without hesitation. Louder source means more voltage going in and the amp likes that better. I don’t like API preamps much for electric guitar, but they’re the bomb for kick drum, new mic (ATM25) or old (AKG D12E). Those transients…API’s handle them so well and the old ones have lower ratio input transformers that keep the gain block from distorting too easily. How much gunk is on that old SM57 you’ve been using for the past 15 years? Didja try a slightly higher output tube in that dbx586 (the stock ones are crap…). See how tough a list could get to build?

So what to do? Modern preamps with lots of gain and transformer I/O are expensive, and vintage amps made to work with ribbons are worse. Experience with a number of different amps and mics is invaluable, but if you don’t have options it’s tough. Fortunately, a lot of modern ribbons have more output that the old ones, and some of the nicer (though more expensive) ones have less of the impedence problem as well. Gain staging is often about the only way out. If you have a ribbon mic up and you’re not getting the kind of signal you feel you need, try lowering the output of the preamp you’re using and put a line amp between the preamp output and the recorder you use. Yes, you need a line amp, but even low cost mixers have line amps. And yes, getting the levels right without distorting one stage or another takes some practice. It may not be perfect, but it may help. And maybe some baffling to better control the real lobe of a figure 8 mic. Home recording rooms often don’t sound too good with figure 8 mics. I generally face a singer down the long dimension of our live room (41 feet) when in front of a ribbon, just to cut down on direct wall reflections.

Or prepare to cough up some dough. It’s a drag, but there it is. Good amplification costs money. Those Universal Audio 1108’s I got from Eddie VanHalen’s old console weren’t cheap, but they sound like nothing that’s currently made, largely because of the transformers in them.

And please, don’t print so hot. Really. You’ll thank me come mix time…

Clava, thanks for sharing your knowledge with us!
The line amp idea may be the thing…

Great detailed info, Clava. Yes, thanks a million! That’s a ‘printer’ for the Home Studio Archive.

Glad you guys got something outa that rambling screed. I guess I’d just add a few points:

mic impedence: The RCA 77dx we were talking about has different output impedences. I notice that Tom’s Presonus Eureka preamp also has some nice choices of variable impedence for mic input. I’d be picking the 150 Ohm setting on that amp, if the mic transformer was using that tap. Or 50 Ohms, if the mic is using the 30 Ohm tap. I get the best ribbon mic response from my old Scully 280 tape machine amps because they have 150 Ohm inputs. Some newer amps have input impedences in the 250 -500 Ohm range, which makes ribbon mic use with them kinda tough. Older amps seem to have the lower input impedences, which is one of the reasons they work a little better for ribbons, particularly older ones like the RCA 77 and 74 Jr. and the older Shures like the 300 and 330.

Preamp topology: I kinda focused on tranformer balanced mic amps, mostly because I like them the best. You don’t need that topology to use ribbon mics though. I have 34 channels of electronically balanced mic amps in my console. You can run ribbons into those inputs, I just don’t happen to like it as much. Also my board sounds real good, but not at the high gain levels you need to run a ribbon effectively. I have to run a second gain stage on the desk for a ribbon too, since the high gain setting gets noisy fast. In addition, I find that transformer inputs have some “give” to them. You can drive them differently than electronically balanced inputs, and they seem to buffer impedence mismatches a little better than opamps. Same with transformer outputs. They add this certain “something” when driven that I just don’t hear with electronically balanced outputs. 'Course, that “something” can translate as it’s own kind of noise (pleasing though I may find it) that doesn’t work for everything. Opamp balanced amps are usually cleaner, which is one reason they get used in lots of mixing consoles. Plus, transformers are big and heavy and good ones are wicked expensive. Neve desks are full of them…just one reason an 8032 costs about the same as a small house.

If you haven’t done so already, I strongly suggest that you keep the specs for all of your equipment in some central and easy to get at location. I have a binder full of all the specs on the mics in the locker, several with info about all of the outboard gear, one for each of the tape machines, and one for the console. I need 'em for tech work, and I keep them handy for outside engineers to refer to when they have a question about how something works, or whether they can plug this thing into that thing and how to do it correctly. The tech library has saved my butt and a session more than once…

Cool, thanks again for your time… one man’s screed is another man’s reference! When I get a ribbon, I’ll bust this info out.

Clava, I noticed that the lower impedence setting lowers the output of the preamp, so I sort of have to crank it up. Is that normal?

Also, remember I have the pre from an Ampex 601? That is at 150, IIRC. I should really get it cleaned up and recapped. I found guys in arizona who do that, and it would have been $400. We’re moving (again) and so money is sort of tight, but… hmmm…mmmmm… :)

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Clava, I noticed that the lower impedence setting lowers the output of the preamp, so I sort of have to crank it up. Is that normal?


I suspect it is. I’m sure there’s a technical reason behind it too, but I’m not really smart enough to do more than guess about it. I do know that my amps with lower input impedence have less output than the more modern ones. I also know that my UA M610 does something similar when you change the impedence setting.

And recapping that 610 shouldn’t be too hard. It helps to have some special tools like a good solder vacuum, but really, it’s not difficult. And new capacitors are stupid cheap. I’m between day jobs until January so I’d even have a look if you were really interested. There’s tons of info on that beast out there, and $400 sounds more than a little steep to me…

Well, for 400 they would rack it and put in balanced and unbalanced outputs, that sort of thing.

I have full schematic, all the relevant tech stuff on it.

OK, here’s a related question: I also have one that was left out in the rain for a few years. I wonder how hard it would be to get a pair in good working condition?

After we move, I should try to work on the first one, and then the second, I think. Unless you are saying you’d give it a go for a price. :)

Left out in the rain? Who leaves a tape machine out in the rain? You mean literally out in the rain, or on a shelf in a garage or a barn or something?

Even for a full rack job, $400 is some not too bad pay on an hourly basis. A 3U rack from Par-Metal (my favorite source) is about $85, an off the shelf linear power supply is about $50 depending on size, connectors and do-dads like a power switch and lamps add another $40 or so. If you want phantom power, I generally use a separate power supply for that which adds another $40, plus maybe $15 for the minimum circuitry to make it work. Right there is $230, and that’s with the addition of a phantom supply (and anybody doing this for a living is building their own power supplies saving some money there…) The remaining $170 at $20 an hour would be just under 9 hours of labor. I guess that’s about right…maybe 10-11 hours is what it could take depending on the condition of the unit and how extensive the mods to a stock Par-Metal case need to be. The metal work takes me the most time, since I don’t have Greenlee punches for XLR connectors. I wouldn’t charge $20 an hour mind you; this was just a little mental exercise so folks can get an idea what something like this entails.

I like racking old equipment and bringing it back to life. Done a few jobs like this (if you couldn’t tell…) and it’s usually a fun little puzzle to work on. Great way to get high quality gear on the cheap too. A new API 512 preamp module is just over $800 retail these days, and that’s without a rack or power supply. That’s right kids…$800 a channel for a raw module…real pro gear is darn expensive. I bought and racked 2 original 1971 vintage API 312 cards for about $700; they’ll hold their value at least as much as the current versions, and some think they sound better.

O.K. Sorry for the hijack. I’ve been doing a bunch of this during my Autumn of no real employment, so it’s been on my mind. You get serious about racking those Ampex’s Tom, send me a PM here or better yet at the TapeOp board, 'cause that’s where I hang my hat most of the time. I’m “djimbe” over there at TOMB…

No problem with the hijack, I asked. :)

Yes, 400 seemed about right to me. As to the one left out in the rain - it really was left out in the rain, behind the guy’s garage. I have no clue why he did that. But I have it now, for free, so I guess that’s OK.

OK, now I want these things up and running at their best. See where these discussions lead?

:D