bcarso
Well-known member
quote: There's no way of using a ribbon motor without a transformer.
You could do a truly-transformerless ribbon preamp, but it would be heroic.
You could do a truly-transformerless ribbon preamp, but it would be heroic.
Active Ribbon Preamp/Impedance Converter Idea - opinions?
- Thread starter Rossi
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khstudio
Well-known member
[quote author="Rossi"][quote author="khstudio"]
I Retract... I guess not since mine already has a tranny :sad:[/quote]
Dunno exacly what you mean. All ribbon mics have trannies. There's no way of using a ribbon motor without a transformer.
If you like the R-121 and would like some extra gain occasionally., you can build PRR's ribbon booster into an external box. PRR's booster was in a different active ribbon thread.[/quote]
I was unaware the 122 used more turns to get the boost... I thought it was the added electronics - to the SAME (121) tranny. This blows my original idea if that's the case.
BTW, Thanks for the tip... I will check PRR's booster out. :thumb:
I Retract... I guess not since mine already has a tranny :sad:[/quote]
Dunno exacly what you mean. All ribbon mics have trannies. There's no way of using a ribbon motor without a transformer.
If you like the R-121 and would like some extra gain occasionally., you can build PRR's ribbon booster into an external box. PRR's booster was in a different active ribbon thread.[/quote]
I was unaware the 122 used more turns to get the boost... I thought it was the added electronics - to the SAME (121) tranny. This blows my original idea if that's the case.
BTW, Thanks for the tip... I will check PRR's booster out. :thumb:
clintrubber
Well-known member
IIRIC someone made a layout for a small PCB back then, but dunno if that was for the last version and/or how it went. Simple compact circuit though, easy to do on 'vero'.khstudio said:
Bye,
Peter
You really don't need a PCB for such a simple circuit, it's very easy to do on veroboard. You should take care to place the input caps as close to each other as possible. I once built a version with the input caps about 2 inches apart which gives excellent radio reception. I think the placement of input caps is an underrated topic in general. In a lot of commercial transformerless preamps, the channel closer to the PSU picks up some hum. Probably wouln't be the case if the both caps were equidistant from the mains transformer.
[quote author="bcarso"]quote: There's no way of using a ribbon motor without a transformer.
You could do a truly-transformerless ribbon preamp, but it would be heroic.[/quote]
Yeah, I seem to remember that you thought about trying the transformerless approach. So let's put it that way: nobody has done it so far, and it seems very unlikely to accomplish with P48. Plus, those 2SC3329 are getting scarce.
You could do a truly-transformerless ribbon preamp, but it would be heroic.[/quote]
Yeah, I seem to remember that you thought about trying the transformerless approach. So let's put it that way: nobody has done it so far, and it seems very unlikely to accomplish with P48. Plus, those 2SC3329 are getting scarce.
[quote author="Rossi"]You really don't need a PCB for such a simple circuit, it's very easy to do on veroboard. You should take care to place the input caps as close to each other as possible. I once built a version with the input caps about 2 inches apart which gives excellent radio reception. I think the placement of input caps is an underrated topic in general. In a lot of commercial transformerless preamps, the channel closer to the PSU picks up some hum. Probably wouln't be the case if the both caps were equidistant from the mains transformer.[/quote]
Mic pre PCB layout matters in dense mixer packages but this situation improved dramatically with the tighter spacing of SMT components. IMO it's more the loop area of PCB traces, not just the distance between components but how you connect the dots. The obvious suggestion is to route traces side by side so area between them is minimal. In multichannel mixers, the design engineer often participates in layout design of one channel and then PCB designer effectively steps and repeats.
Properly executed the mic pre closest to the PS will have adequately low hum floor, but it's no accident that line levels usually occupy upper input channels. FWIW mixer noise floors are specified by worst channel, not typical or best.
Power supply transformers in small mixers are manageable. For perspective try designing powered mixers with transformer mic inputs and 100V audio output transformers all inside a single compact chassis while using budget parts. The built in power amp means more power transformer related magnetic field and magnetic coupling from 100V output to mic level inputs can cause HF oscillation.
JR
Mic pre PCB layout matters in dense mixer packages but this situation improved dramatically with the tighter spacing of SMT components. IMO it's more the loop area of PCB traces, not just the distance between components but how you connect the dots. The obvious suggestion is to route traces side by side so area between them is minimal. In multichannel mixers, the design engineer often participates in layout design of one channel and then PCB designer effectively steps and repeats.
Properly executed the mic pre closest to the PS will have adequately low hum floor, but it's no accident that line levels usually occupy upper input channels. FWIW mixer noise floors are specified by worst channel, not typical or best.
Power supply transformers in small mixers are manageable. For perspective try designing powered mixers with transformer mic inputs and 100V audio output transformers all inside a single compact chassis while using budget parts. The built in power amp means more power transformer related magnetic field and magnetic coupling from 100V output to mic level inputs can cause HF oscillation.
JR
bcarso
Well-known member
[quote author="Rossi"] those 2SC3329 are getting scarce. [/quote]
Is that true? I hadn't heard that. Are they being discontinued? That would be a shame. I should think if Behringer and NAD are using them they would keep making them (and the PNP 2SA1316).
You are right though that P48 is particularly challenging, with a maximum extractible power of 169mW; the best transistors need substantial current for best performance with three-tenths of an ohm source Z (e sub n of that source is only 70pV/sq rt Hz !). With a perfectly efficient power converter to get 50mA for the Qs you have only 3.3V available. That would be for a design that at best might achieve a 3dB noise figure.
But if you are going to that much trouble already, convenience of phantom power is probably not the highest priority.
[/quote]Is that true? I hadn't heard that. Are they being discontinued? That would be a shame. I should think if Behringer and NAD are using them they would keep making them (and the PNP 2SA1316).
You are right though that P48 is particularly challenging, with a maximum extractible power of 169mW; the best transistors need substantial current for best performance with three-tenths of an ohm source Z (e sub n of that source is only 70pV/sq rt Hz !). With a perfectly efficient power converter to get 50mA for the Qs you have only 3.3V available. That would be for a design that at best might achieve a 3dB noise figure.
But if you are going to that much trouble already, convenience of phantom power is probably not the highest priority.
[quote author="bcarso"][quote author="Rossi"] those 2SC3329 are getting scarce. [/quote]
Is that true? I hadn't heard that. Are they being discontinued? That would be a shame. I should think if Behringer and NAD are using them they would keep making them (and the PNP 2SA1316).
[/quote]
I don't know anything definite, but I ordered some 2SC3329 at a place that had listed them, and they later informed me (after they got the money) that they can't get them, right now. I asked at another (more reputable) place, and they told me right away, that it is "undeliverable" - which can mean any number of things, but I'm afraid, it could mean Toshiba has ceased production. Possibly a RoHS issue?
Behringer now use a different low Rbb transistor, with the somewhat strange designation 2SV888 (they even put it into their press release for their new mixer line). I recently found some very basic information here: http://www.coolaudio.com/products.html
Apparently Behringer now fabricate their own semiconductors. :shock: For all I know Coolaudio belongs to Behringer.
[/quote]Is that true? I hadn't heard that. Are they being discontinued? That would be a shame. I should think if Behringer and NAD are using them they would keep making them (and the PNP 2SA1316).
[/quote]
I don't know anything definite, but I ordered some 2SC3329 at a place that had listed them, and they later informed me (after they got the money) that they can't get them, right now. I asked at another (more reputable) place, and they told me right away, that it is "undeliverable" - which can mean any number of things, but I'm afraid, it could mean Toshiba has ceased production. Possibly a RoHS issue?
Behringer now use a different low Rbb transistor, with the somewhat strange designation 2SV888 (they even put it into their press release for their new mixer line). I recently found some very basic information here: http://www.coolaudio.com/products.html
Apparently Behringer now fabricate their own semiconductors. :shock: For all I know Coolaudio belongs to Behringer.
bcarso
Well-known member
Yeah could be RoHS at work.
I sincerely doubt Behringer is making semis though.
I sincerely doubt Behringer is making semis though.
mikep
Well-known member
[quote author="bcarso"]
You are right though that P48 is particularly challenging, with a maximum extractible power of 169mW[/quote]
if you are going to really push the performance envelope and need more current, an external PSU even for a solid state mic is justifiable. make it suitably expensive and vintage-styled and consumers will go for it.
You are right though that P48 is particularly challenging, with a maximum extractible power of 169mW[/quote]
if you are going to really push the performance envelope and need more current, an external PSU even for a solid state mic is justifiable. make it suitably expensive and vintage-styled and consumers will go for it.
[quote author="bcarso"]Yeah could be RoHS at work.
I sincerely doubt Behringer is making semis though.[/quote]
http://www.pro-music-news.com/html/02/e00726be.htm
looks like Uli bought Intersils class D patent portfolio which had some old Harris IP in it too btw called "coolaudio" some time ago (10 years?).
There may be more than one coolaudio...but those semis look like old obsoleted or knocked off parts perhaps ripped off before they were off patent.
Now Uli is using and pimping a transistor sold by "coolaudio", that doesn't even have a spec sheet. Hmmm Perhaps one of the obsoleted low noise parts, with new leads.
Sounds like there may be some connection, but what (Red Chip?) :?:
JR
I sincerely doubt Behringer is making semis though.[/quote]
http://www.pro-music-news.com/html/02/e00726be.htm
looks like Uli bought Intersils class D patent portfolio which had some old Harris IP in it too btw called "coolaudio" some time ago (10 years?).
There may be more than one coolaudio...but those semis look like old obsoleted or knocked off parts perhaps ripped off before they were off patent.
Now Uli is using and pimping a transistor sold by "coolaudio", that doesn't even have a spec sheet. Hmmm Perhaps one of the obsoleted low noise parts, with new leads.
Sounds like there may be some connection, but what (Red Chip?) :?:
JR
> There's no way of using a ribbon motor without a transformer.
Bah. Put the raw ribbon right in front of a Fender Twin turned to "11", pluck hard, mix it with a snare-happy drummer, Pro-Tool it for a month, nobody will notice a 30dB noise figure.
> You could do a truly-transformerless ribbon preamp, but it would be heroic.
Somewhere I penciled a tube tranformerless preamp. I think it worked out (for very good noise figure) to a cube 7 feet on a side. Which raises other noise issues: diffraction if too near the mike, blower noise if it is in the same room with the mike, or cable loss if mounted outside the room. Very Heroic.
Bah. Put the raw ribbon right in front of a Fender Twin turned to "11", pluck hard, mix it with a snare-happy drummer, Pro-Tool it for a month, nobody will notice a 30dB noise figure.
> You could do a truly-transformerless ribbon preamp, but it would be heroic.
Somewhere I penciled a tube tranformerless preamp. I think it worked out (for very good noise figure) to a cube 7 feet on a side. Which raises other noise issues: diffraction if too near the mike, blower noise if it is in the same room with the mike, or cable loss if mounted outside the room. Very Heroic.
clintrubber
Well-known member
[quote author="JohnRoberts"][quote author="bcarso"]I sincerely doubt Behringer is making semis though.[/quote][/quote]
At least they say they do:
[quote author="[url]http://www.coolaudio.com/aboutus.html[/url]"]We are a global semicon company with foundry services and cooperations with leading IC manufacturers, as well as fab-lite and fab-less semiconductor suppliers in USA, China, Hong Kong, Taiwan and Singapore[/quote]
The article suggests 2000, but then most likely there will have been previous mentionings of it here but those that I recall are faily recent.
Bye,
Peter
At least they say they do:
[quote author="[url]http://www.coolaudio.com/aboutus.html[/url]"]We are a global semicon company with foundry services and cooperations with leading IC manufacturers, as well as fab-lite and fab-less semiconductor suppliers in USA, China, Hong Kong, Taiwan and Singapore[/quote]
It's not fully clear to me how long that coolaudio exists already (ie, when Behringer 'moved in').
The article suggests 2000, but then most likely there will have been previous mentionings of it here but those that I recall are faily recent.
Bye,
Peter
[quote author="bcarso"]I sincerely doubt Behringer is making semis though.[/quote]
Well, not in the sense that they're designing anything new, but look at the coolaudio portfolio: as far as I can tell it's nothing but parts that Behringer uses extensively. Note for instance the BBD chips which they use in their guitar pedals. Or the 2159 VCAs which they use both in rack gear and floor pedals (I own a Behringer tremolo pedal that uses a Coolaudio VCA). Same with opamps: 4580 for "pro" audio gear and 4558 for guitar pedals. Also, the Coolaudio portfolio follows Behringer's strategy: same but cheaper.
Here's a press release about B's aquisition of Coolaudio: http://journals.enotes.com/music-trades-journals/62703215
Interestingly enough, I don't see any of the class D products on the Coolaudio website.
Well, not in the sense that they're designing anything new, but look at the coolaudio portfolio: as far as I can tell it's nothing but parts that Behringer uses extensively. Note for instance the BBD chips which they use in their guitar pedals. Or the 2159 VCAs which they use both in rack gear and floor pedals (I own a Behringer tremolo pedal that uses a Coolaudio VCA). Same with opamps: 4580 for "pro" audio gear and 4558 for guitar pedals. Also, the Coolaudio portfolio follows Behringer's strategy: same but cheaper.
Here's a press release about B's aquisition of Coolaudio: http://journals.enotes.com/music-trades-journals/62703215
Interestingly enough, I don't see any of the class D products on the Coolaudio website.
whoaudio.... There is the "coolaudio" class D portfolio that was bought from Intersil, and some other "coolaudio" hifi-install business(?) that seems to have gone away. The "coolaudio" semiconductors definitely walks, quacks, and smells like it's part of grandmaster B-duck's empire, but they don't make any connection in writing that I see.
Only paper connection I see is a common trademark registry/claim (coolaudio and behringer both in Red Chip portfolio of names).
The terms on the coolaudio semiconductor site reads like a pirate's mantra.. Like you're on your own if there's any IP claims on the parts (we don't say where they came from) we sold you. They claim rights to name coolaudio, in the name of whoever owns the rights to coolaudio... ??? I paraphrase but it's not far off. Some lawyer must have got a good laugh out of writing that poop.
Agreed parts are old soldiers. BBD technology was originally Phillips licensed to Matsushita, but that was in '70s. Early dbx vca stuff probably expired IP too. In China one can only imagine how much of that kind of activity is/was going on, before IP expired.
If they published a data sheet on the low noise PNP we could probably identify it. I wouldn't mind if they bring back the 2SB737.
JR
I didn't bother to whois on the coolaudio semi site, that might reveal a connection but isn't definitive if it doesn't.
Only paper connection I see is a common trademark registry/claim (coolaudio and behringer both in Red Chip portfolio of names).
The terms on the coolaudio semiconductor site reads like a pirate's mantra.. Like you're on your own if there's any IP claims on the parts (we don't say where they came from) we sold you. They claim rights to name coolaudio, in the name of whoever owns the rights to coolaudio... ??? I paraphrase but it's not far off. Some lawyer must have got a good laugh out of writing that poop.
Agreed parts are old soldiers. BBD technology was originally Phillips licensed to Matsushita, but that was in '70s. Early dbx vca stuff probably expired IP too. In China one can only imagine how much of that kind of activity is/was going on, before IP expired.
If they published a data sheet on the low noise PNP we could probably identify it. I wouldn't mind if they bring back the 2SB737.
JR
I didn't bother to whois on the coolaudio semi site, that might reveal a connection but isn't definitive if it doesn't.
[quote author="JohnRoberts"] I wouldn't mind if they bring back the 2SB737.[/quote]
In fact I was wondering if the ominous 2SV888 isn't really a 2SB737. Behringer used it quite extensively while it was still in production. They lather switched to the 2SA1084 and 2SA1316. There may have been others in between.
I'm pretty certain there is a direct connection between Coolaudio and Behringer, even though they don't mention the big B on their website. Just buy a cheapo Behringer floor pedal, you'll find Coolaudio chips in almost any of them. As I said, I have a tremolo unit that thas a Coolaudio VCA and when I looked inside the chorus pedal I bought for my brother, there were Coolaudio BBD chips.
In fact I was wondering if the ominous 2SV888 isn't really a 2SB737. Behringer used it quite extensively while it was still in production. They lather switched to the 2SA1084 and 2SA1316. There may have been others in between.
I'm pretty certain there is a direct connection between Coolaudio and Behringer, even though they don't mention the big B on their website. Just buy a cheapo Behringer floor pedal, you'll find Coolaudio chips in almost any of them. As I said, I have a tremolo unit that thas a Coolaudio VCA and when I looked inside the chorus pedal I bought for my brother, there were Coolaudio BBD chips.
clintrubber
Well-known member
[quote author="Rossi"]Sound & Recording is from the same publishing house as Keyboards.
Maybe you can find another newsstand that carries it.[/quote]
I forgot to visit the other big one here in town... I passed by tonight and remembered this thread and as it happened they had S&R. :thumb:
Needless to say that because of the Mainzelmännchen it was located at the childrens corner.... I should remember this when I go for the next part next month.
Maybe you can find another newsstand that carries it.[/quote]
I forgot to visit the other big one here in town... I passed by tonight and remembered this thread and as it happened they had S&R. :thumb:
Needless to say that because of the Mainzelmännchen it was located at the childrens corner.... I should remember this when I go for the next part next month.
clintrubber
Well-known member
[quote author="Rossi"]BTW. The current issue also features a RB100 review, but it's a rather short one ("infotest").[/quote]
I spotted that, nice. T-prices are quite insane for this one and the RM700....
I spotted that, nice. T-prices are quite insane for this one and the RM700....
The second part of "Pimp My Ribbon" is out. The magazine appeared about a week ago, so it ought to have arrived in the surrounding EU states by now.
Unfortunately the Mainzelmännchen graphics were scaled down due to space limitations. It's still 6 pages of ribbon fun including:
- converting certain models to active operation using a simple impedance converter (some models had an overwound 1:80 transformer resulting in a 2600 ohms output impedance)
- winding your own 1:100 active ribbon transformer using the stock transformer's core. No fancy machinery needed.
- PRR's ribbon booster circuit in a new version (see above) including a chart of usable transistors.
- sound samples of all the mods in both issues. (Just acoustic guitar, nothing fancy).
Of course, there's losts of other stuff in the mag that's worth reading. Here's the web preview/contents page: www.soundandrecording.de.
[For those who just tuned in: Despite the name "Sound & Recording", the mag is in German.]
End of commercial break. :grin:
Unfortunately the Mainzelmännchen graphics were scaled down due to space limitations. It's still 6 pages of ribbon fun including:
- converting certain models to active operation using a simple impedance converter (some models had an overwound 1:80 transformer resulting in a 2600 ohms output impedance)
- winding your own 1:100 active ribbon transformer using the stock transformer's core. No fancy machinery needed.
- PRR's ribbon booster circuit in a new version (see above) including a chart of usable transistors.
- sound samples of all the mods in both issues. (Just acoustic guitar, nothing fancy).
Of course, there's losts of other stuff in the mag that's worth reading. Here's the web preview/contents page: www.soundandrecording.de.
[For those who just tuned in: Despite the name "Sound & Recording", the mag is in German.]
End of commercial break. :grin:
Here's some Mainzelmännchen artwork from the articles:
Opening graphics for the second part (Attack of the Noise Monster):
Closing graphics:
No animals were harmed, but I look pretty exhausted:
Opening graphics for the first installment:
Opening graphics for the second part (Attack of the Noise Monster):
Closing graphics:
No animals were harmed, but I look pretty exhausted:
Opening graphics for the first installment:
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