The real TAPE EMULATION circuit
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bradb
Well-known member
http://www.gearslutz.com/board/showthread.php3?t=39806
its funny, people are really angry about this box too. There are alot of negative posts at gearslutz too.
maybe the concept is too radical?
i wish the big heavies here on the board would comment.
its funny, people are really angry about this box too. There are alot of negative posts at gearslutz too.
maybe the concept is too radical?
i wish the big heavies here on the board would comment.
pucho812
Well-known member
Guys. I had a nice semi long discussion at AES with rupert about is portico tape emulation circuit. For starters you can get one for a week tryout and if you like it keep it and pay for it or return it. As for the heads being together VS real tape? The rupert unit utlizes a real emphasis and deemphasis(sp) circuit like a tape machine and by magnitizing the heads your creating that analog magnetic field VS emulating with 0"s and 1"S. It sounds good IMO. Those gear slutz people are trendy and will bash anything non analog just because it's the thing to do. like being able to hear autotune or stuff like that. Yeah I would love to use tape on everything but it's not possible not anymore especially with budgets getting smaller and smaller or bands getting worse and worse in being able to play . Tape is now an effect. The box makes light of that. Can't fault a man for giving peopole what they want at a fair price. It will never replace a good 1/2" 2 track but it does sound good.
sismofyt
Well-known member
that's a bit hard on the GS people. it's also trendy to percieve Rupert as a god. the emphasis/deemphasis does certianly not make the tape sound, it's just eq. saturation of the heads sound horrible compared to saturating the actual tape.
tape is not an effect. protools is
tape is not an effect. protools is
stickjam
Well-known member
[quote author="sismofyt"]i know about that Rupert thing, i do live on the same planet as the rest of you. i just don't understand how the 'tape sound' can be had without tape. i don't think using just heads is enough, when you're overloading a tapemacine you're overloaded the tape, not the heads (unless it's a semi pro)
so by all means go ahead, i just do not think it's possible. why do you?[/quote]
I'm with you there.
I use a big 2-track deck and do the usual thing--record direct into the DAW, then play back two tracks at a time through the 2-track, recording two new tracks that I drag back in time to match the original; mix with the new tracks after archiving the original ones. Time-consuming, but sweet. I've recorded live through both--cutting two direct tracks and two tape-delayed tracks--does the same thing quicker--just don't try punch-ins! :roll:
Before I got a real Otari 2-track, I tried an experiment several years ago with an old 2-head cassette deck whose transport's logic had died. It was a really good model in its day--the kind that actually had two independent heads--not like new ones with record/playback grafted together. I took some direct-recorded drum and other instrument tracks and did the tape "reamping" I described above with the transport hotwired to work.
Then I pulled out the heads--adjustment mounts and all and mounted them facing each other on an aluminum plate. I adjusted alignment and repeated the experiment on two other tracks. I did get a saturation effect, but the tape made the difference. It felt more like a transformer than anything, IIRC.
What I didn't try is putting a bit of tape media between the two. One would think that it wouldn't really be the end of the story, because as I understand it, the amount of magnetic flux the record head generates isn't equivalent to the flux changes generated by the tape passing the playback head. That much was obvious in my experiment, as I recall I had to dial back levels to produce the same signal amplitude to the DAW.
I wish I knew where those experimental tracks are--if I kept them or not. I'll check, although I don't have a lot of confidence they still exist--my studio recordkeeping wasn't too good back then.
--Bob
so by all means go ahead, i just do not think it's possible. why do you?[/quote]
I'm with you there.
I use a big 2-track deck and do the usual thing--record direct into the DAW, then play back two tracks at a time through the 2-track, recording two new tracks that I drag back in time to match the original; mix with the new tracks after archiving the original ones. Time-consuming, but sweet. I've recorded live through both--cutting two direct tracks and two tape-delayed tracks--does the same thing quicker--just don't try punch-ins! :roll:
Before I got a real Otari 2-track, I tried an experiment several years ago with an old 2-head cassette deck whose transport's logic had died. It was a really good model in its day--the kind that actually had two independent heads--not like new ones with record/playback grafted together. I took some direct-recorded drum and other instrument tracks and did the tape "reamping" I described above with the transport hotwired to work.
Then I pulled out the heads--adjustment mounts and all and mounted them facing each other on an aluminum plate. I adjusted alignment and repeated the experiment on two other tracks. I did get a saturation effect, but the tape made the difference. It felt more like a transformer than anything, IIRC.
What I didn't try is putting a bit of tape media between the two. One would think that it wouldn't really be the end of the story, because as I understand it, the amount of magnetic flux the record head generates isn't equivalent to the flux changes generated by the tape passing the playback head. That much was obvious in my experiment, as I recall I had to dial back levels to produce the same signal amplitude to the DAW.
I wish I knew where those experimental tracks are--if I kept them or not. I'll check, although I don't have a lot of confidence they still exist--my studio recordkeeping wasn't too good back then.
--Bob
bradb
Well-known member
I see a problem with putting tape between the write and read heads (using the heads together scheme) When youre printing to tape, that info stays on the tape until its erased. After just a few seconds, I'd expect some sort of audio mud to come out. but then again, audio doesn't come out until the tape is dragged across the read head. hmmmmm
I also was worried that the whole tape effect is coming mostly from the magnetic tape itself.... bummer! thanks for the info stickjam...
I also was worried that the whole tape effect is coming mostly from the magnetic tape itself.... bummer! thanks for the info stickjam...
sismofyt
Well-known member
maybe one could make a gizmo that didn't wear out the tape so much? and one could omit the big reel motors and just settle for the capstan, using a tapeloop like a tapecho. i hate running out of tape in the middle of a truly dubtastic, hands on tapedelay
i wonder if it would be possible to make something without a moving tape? like; input head - 'tape medium' - output head?
i wonder if it would be possible to make something without a moving tape? like; input head - 'tape medium' - output head?
bradb
Well-known member
something like a tape loop that was erased after recorded to and then read back off of? (poor grammar, i hope this is clear)
sounds like a good idea... still you'd have to deal with alignment and head wear and all that. but it would simplify things mechanically..
sounds like a good idea... still you'd have to deal with alignment and head wear and all that. but it would simplify things mechanically..
sismofyt
Well-known member
well, that's how tapedelays work. the signal does get erased after being 'recorded'. i'm really pondering about not using a movable tape. just pondering, as i think using actual tapemachines are still the way to go
chrissugar
Well-known member
The tape delay idea is not a good one in my opinion because of three factors:
1- it is not a realtime effect, you will always have a delay between in and out,
2- tape will degrade very soon,
3- you stil have to maintain it (change tape, align heads, moving parts)
In that case a real tape recorder is the best solution.
But I think the idea is to find a solution that can do something similar even if it would be only 80% of the positive aspects of the tape recorder.
chrissugar
1- it is not a realtime effect, you will always have a delay between in and out,
2- tape will degrade very soon,
3- you stil have to maintain it (change tape, align heads, moving parts)
In that case a real tape recorder is the best solution.
But I think the idea is to find a solution that can do something similar even if it would be only 80% of the positive aspects of the tape recorder.
chrissugar
G
Guest
Guest
bumping this thread
Did anybody ever get anywear on implementing a Portico type solution (ie some actual mag heads) into the signal path?
Did anybody ever get anywear on implementing a Portico type solution (ie some actual mag heads) into the signal path?
pucho812
Well-known member
yeah rupert neve did. :green:
SUPERMAGOO
Well-known member
i think ....good tape effect it's similar to lo1166 transformer effect. my stereo out of DAW conect to 1/2 ne*e 1272.I feel beter audio.
Kingston
Well-known member
I'm sorry to deviate this thread slightly to the digital side of things, but I have some experience in the field, and would like to offer some insight, and at the same time recap (pun intended) the thread this far. The whole thing is written with the "tape as an effect" mentality. Sorry if you don't like it.
1. I/O electronics.
This is the least important bit in the overall sound, but it order to drive those heads a basic gain and attenuation is needed. This is the easiest thing for us to replicate as there's a choice of multitudes of good line amps. In digital form this type of gain staging hasn't been emulated as of yet, and that's what a soon to be released plugin of mine will do. I've christened the effect as intra-modulation (IM) and it somewhat captures the interaction between transformers and gain stages of electronics, and several other secondary effects that go nicely "wrong" in any analogue circuit.
2. pre-emphasis/de-emphasis.
Exteremely important factor in the saturation performance and should not be omitted. Also easy to replicate in either digital or analog form. What's your favourite emphasis curves? Simply DIY that or similarly do a digital oversampled filter using the same curves. This is the only place where impulses of the real units would do any good (and even then only if sampled at both stages, which would be difficult). Dynamic convolution is only good to recapture the filtering performance, and it might as well be done algorithmically instead (cheaper DSP wise, and easier). This was done in the voxengo TapeBus mentioned earlier in this thread, and it features, for example, Studer B67 impulses by yours truly. Its sound still leaves a lot to be desired.
3. Magnetisation.
There's very little info on how to do this digitally, and I'm doing research on the subject as we speak. Electronically one might as well do the portico thing and use real tape heads if one is willing to gut working units. If any of you manages to do this, I would be very interested in any kind of analytical measurements on it. Basically one could emulate this as a waveshaper in digital form, but the actual response curves and shapes are unavailable in a pure magnetisation form. The saturation dynamic curves are always expressed in conjunction with the tape media curves, unfortunately. Maybe one of you would have data already available?
4. Tape media.
Generally when tapes are emulated magnetisation and tape media characteristics are filed under "saturation". This is a mistake, since both play nearly equal role in tape sound. Tape media is most likely impossible to emulate electronically unless using tape loops, but that creates the many problems already covered earlier in this thread. Digital implementation is another thing. I'm doing research on this subject as well.
Basically the media has little influence on the sound when it's not driven (well, it does a little actually). Things change drastically when the tape is stressed, and we start to hear all the good sounding fluctuations that now get exaggerated. Using a separate digital waveshaper with time-based randomisation chanracteristics should work. The model should be dynamic, ie high saturation exaggerates the "smear" while quiet sounds get very little of it.. Problems arise when determining the "right" fluctuations as it varies from tape manufacturer to another. Data on this is mostly unavailable, as it's time based and difficult to measure.
5. (concerning only digital implementation)
Analogue electronics produce lots of secondary side effects: thermal coupling, physical limits of transistors/diodes etc. While it isn't anything to worry about when DIYing a tape effect, it has to be modelled separately in a digital form. I already mentioned IM, and since these effects are minor in the tape sound, IM is perfectly adequate to model them.
What did I miss?
*passes the baton*
1. I/O electronics.
This is the least important bit in the overall sound, but it order to drive those heads a basic gain and attenuation is needed. This is the easiest thing for us to replicate as there's a choice of multitudes of good line amps. In digital form this type of gain staging hasn't been emulated as of yet, and that's what a soon to be released plugin of mine will do. I've christened the effect as intra-modulation (IM) and it somewhat captures the interaction between transformers and gain stages of electronics, and several other secondary effects that go nicely "wrong" in any analogue circuit.
2. pre-emphasis/de-emphasis.
Exteremely important factor in the saturation performance and should not be omitted. Also easy to replicate in either digital or analog form. What's your favourite emphasis curves? Simply DIY that or similarly do a digital oversampled filter using the same curves. This is the only place where impulses of the real units would do any good (and even then only if sampled at both stages, which would be difficult). Dynamic convolution is only good to recapture the filtering performance, and it might as well be done algorithmically instead (cheaper DSP wise, and easier). This was done in the voxengo TapeBus mentioned earlier in this thread, and it features, for example, Studer B67 impulses by yours truly. Its sound still leaves a lot to be desired.
3. Magnetisation.
There's very little info on how to do this digitally, and I'm doing research on the subject as we speak. Electronically one might as well do the portico thing and use real tape heads if one is willing to gut working units. If any of you manages to do this, I would be very interested in any kind of analytical measurements on it. Basically one could emulate this as a waveshaper in digital form, but the actual response curves and shapes are unavailable in a pure magnetisation form. The saturation dynamic curves are always expressed in conjunction with the tape media curves, unfortunately. Maybe one of you would have data already available?
4. Tape media.
Generally when tapes are emulated magnetisation and tape media characteristics are filed under "saturation". This is a mistake, since both play nearly equal role in tape sound. Tape media is most likely impossible to emulate electronically unless using tape loops, but that creates the many problems already covered earlier in this thread. Digital implementation is another thing. I'm doing research on this subject as well.
Basically the media has little influence on the sound when it's not driven (well, it does a little actually). Things change drastically when the tape is stressed, and we start to hear all the good sounding fluctuations that now get exaggerated. Using a separate digital waveshaper with time-based randomisation chanracteristics should work. The model should be dynamic, ie high saturation exaggerates the "smear" while quiet sounds get very little of it.. Problems arise when determining the "right" fluctuations as it varies from tape manufacturer to another. Data on this is mostly unavailable, as it's time based and difficult to measure.
5. (concerning only digital implementation)
Analogue electronics produce lots of secondary side effects: thermal coupling, physical limits of transistors/diodes etc. While it isn't anything to worry about when DIYing a tape effect, it has to be modelled separately in a digital form. I already mentioned IM, and since these effects are minor in the tape sound, IM is perfectly adequate to model them.
What did I miss?
*passes the baton*
maxwall
Well-known member
- Joined
- Nov 17, 2004
- Messages
- 1,134
It cant be emulated , so just go out and restore a good ole tape machine for your studio. This will make the demand for parts come back so all of us can run tape again without concern.
Also infinite sampling rate too and no more hardware upgrades.
Also infinite sampling rate too and no more hardware upgrades.
Kingston
Well-known member
I wouldn't carve that in stone yet, referring to my previous post and many other additional tidbits already covered in this thread. Sure it might seem that way, but how would we ever have any progress if people refuse to even try it? :wink:
Besides, these experiments might result in other surprising applications, too.
mikep
Well-known member
I just read this thread. some really good ideas, but nobody hit on this yet: beyond the transformer-like magnetic saturation effects of the tape recording process there is the thing that happens when excitation is removed and the STORAGE phase occurs. the flux drops a bit on the tape. there is *another* hysteresis going on here. this is not present in transformers or the back-to-back heads arrangement. how do you get a similar effect to that? do you even want to? I say maybe not.
Ive made a bunch of recordings on tape using very good tape machines. 3m, studer, MCI etc. In addition to what a tape recording does NOT do, compared to digital, I have witnessed many times that it can do something wonderful to a prevoiusly recorded digital source. sometimes that effect is very beneficial to the program material, sometimes not! when laying back to tape in mastering (what I now mostly do) there are ALWAYS tradeoffs. there is no free lunch, even if something improves some other aspect will suffer. To romanticise the particular effect is a bit misguided, in my opinion. If you are going to try to do this, realize tape is not perfect. It could be even better than the real thing. I have a tape machine. I have transformer coupled line amps. I can still see the appeal of something that will let us achieve tape-like saturation with less loss of transparency.
who knows if leaving out the "storage hysteresis" of tape will help in the regard of transparency, I'm just saying don't be discouraged by the fact that it is not practical to include it. tape is not magic!
one more thing, I have used those crappy CD-cassettetape adapter things for special effect. this is essentialy back to back tape heads+ whatever cassette deck electronics you use. The sound is not really like tape and it is not hi-fi at all (even using a pro cassette deck). it is very useful for certain things though. It can add brightness in a cool way that EQ alone cannot match. I have used it with great success to distort drums and as a parallel feed on a rock bass guitar track to add grit. I wonder what the portico sounds like.
mike p
Ive made a bunch of recordings on tape using very good tape machines. 3m, studer, MCI etc. In addition to what a tape recording does NOT do, compared to digital, I have witnessed many times that it can do something wonderful to a prevoiusly recorded digital source. sometimes that effect is very beneficial to the program material, sometimes not! when laying back to tape in mastering (what I now mostly do) there are ALWAYS tradeoffs. there is no free lunch, even if something improves some other aspect will suffer. To romanticise the particular effect is a bit misguided, in my opinion. If you are going to try to do this, realize tape is not perfect. It could be even better than the real thing. I have a tape machine. I have transformer coupled line amps. I can still see the appeal of something that will let us achieve tape-like saturation with less loss of transparency.
who knows if leaving out the "storage hysteresis" of tape will help in the regard of transparency, I'm just saying don't be discouraged by the fact that it is not practical to include it. tape is not magic!
one more thing, I have used those crappy CD-cassettetape adapter things for special effect. this is essentialy back to back tape heads+ whatever cassette deck electronics you use. The sound is not really like tape and it is not hi-fi at all (even using a pro cassette deck). it is very useful for certain things though. It can add brightness in a cool way that EQ alone cannot match. I have used it with great success to distort drums and as a parallel feed on a rock bass guitar track to add grit. I wonder what the portico sounds like.
mike p
MartyMart
Well-known member
I'm a bit late to the party, so excuse me for not reading every reply ...
I found the Steinberg Magneto plug in to be acceptable across various
"tracks" but not over a master/mix.
I've sent mixes from HD or DAT to a 1/2 inch stereo machine running at 30ips and got great results.
Hiring / blagging a favour now and again is possible, I wouldn't need one all the time.
The sound, in particular for Rock/Gtr based tracks was fantastic !
http://www.elixant.com/~stompbox/smfforum/index.php?topic=25077.0
Here's a speaker saturation circuit and an address to where the tape sat
circuit originaly came from ( on the schem )
This works great when using a gtr based amp/speaker sim, with this at the back end
MM.
I found the Steinberg Magneto plug in to be acceptable across various
"tracks" but not over a master/mix.
I've sent mixes from HD or DAT to a 1/2 inch stereo machine running at 30ips and got great results.
Hiring / blagging a favour now and again is possible, I wouldn't need one all the time.
The sound, in particular for Rock/Gtr based tracks was fantastic !
http://www.elixant.com/~stompbox/smfforum/index.php?topic=25077.0
Here's a speaker saturation circuit and an address to where the tape sat
circuit originaly came from ( on the schem )
This works great when using a gtr based amp/speaker sim, with this at the back end
MM.
maxwall
Well-known member
- Joined
- Nov 17, 2004
- Messages
- 1,134
I don't consider emulation progress its simply a shift in the nature of manufacturing for corporate bottom line cost accounting vs profit. That is something you can carve in stone. Did analog tape emulate anything ?
The thought of coming up with something new is the result of progress.
If the technologies could be used to improve tape sound - great.
It should not be based on a software core though. None of these dependencies on upgrade after upgrade. Like software based junk.
Yeah its convenient and space saving, but whats going to happen next.
at least make it recycle-able and green friendly.
Keep trying - sure no objections to that. Great discoveries are possible.
The thought of coming up with something new is the result of progress.
If the technologies could be used to improve tape sound - great.
It should not be based on a software core though. None of these dependencies on upgrade after upgrade. Like software based junk.
Yeah its convenient and space saving, but whats going to happen next.
at least make it recycle-able and green friendly.
Keep trying - sure no objections to that. Great discoveries are possible.
