I have started using my Revox B77 MKII for bouncing down my ITB mixes. Once recorded, they sound phenomenal (my deck is uncalibrated and running at 15IPS, using NOS BASF 911), the deck gives a softening effect to the mix which sounds pleasing, and the lowend attains a certain bloom. However, when I then re-record this back to my DAW, the resulting audio file loses some of the charm, namely in the low end..

I am using a SPL Crimson 3, capturing the tape at 96k like we do at the office. However, at my project cave, I don't have the luxury of using DAD (Danish Audio Digital) conversion on the way in, nor do I have a meellion dollar clocking like we have in the office.

So, to cut the long story short:

1) Do you think I'm tripping? As in, the sonic differences are placebo/confirmation bias/etc?
2) Is it possible that my old Crimson 3 just isnt up to the task?

I will retest this later by taking my JoeCo Cello to the project cave, and testing digitization with that one at 96k..

PS: I am deliberately using my Revox uncalibrated, as I fear it will lose some of its "mojo" if properly calibrated.. I specifically like to use the tape deck, because it makes things sound "worse" in a pleasing way!

bump

No tape users here ever experienced problems/issues recapturing their analog tape takes?

I'll chime as a long-time tape user, and I spent some time making transfers from tape to digital.

I do not know the SPL Crimson, so can not comment on its quality of AD/DA - however, I would not think that you would lose much in terms of low-end or other sonic attributes.

Have you tried a simple loopback recording of audio from your DAW via Crimson Outputs to Inputs? Without the tape deck in the circuit and see if the Crimson captures audio as you'd like.

I would always calibrate my tape machines, as yes it may have a certain charm right now - but that may change over time, and you may never get that sound back. Calibrated is repeatable and you know where you stand. If your current calibration is giving pleasing results, you can always make a note of the calibration and have this repeatable. It is also possible that one or both tracks are adding more low-end through.

The REVOX B77 MKII is an great machine!

Thanks for your thoughts.

That's a good point regarding the calibration. I should print test tones on a tape while it sounds the way it does, these should allow me to dial this specific "miscalibration" back in later, right?

I should get it serviced anyways.. the transport is making squeaky sounds on repro, probably needs some TLC..

As for the loopback test, I dont know how I could test the capture.. as the lowend bloom coming off the tape is something I am unable to recreate ITB.. So its kind of an chicken or the egg problem..

I have noticed a similar phenomenon occurring also with vinyl records.. this signal conditioning effect, where things round out and the lowend gains a slight "halo" or bloom, if you will, is also present on many vinyl versions of released music I have on CD & vinyl both.. I listen to analogue tape audio at least 20 hours a week, and have been doing this for several years now.. there is something intriguing about the electromagnetic sound transmission medium, which I feel PCM digital might not always catch accurately.. Vinyl music is also electromagnetic in a way, as a vinyl cart uses magnets when converting the vibrations to voltages.. its hard to put into words without starting to sound like an audiophile.. and I detest audiophile "magical thinking" when it comes to audio engineering..

The effect I am trying to describe might have something to do with phase shift..? As I seem to recall experiencing something slightly similar when utilizing certain graphic EQs.. which are notorious for introducing radical phase shifts to the program material, right?

With regards to placebo, emotional "haze" of using tape: I always try to take my right brain out of it when I'm trying to objectively understand what's happening with a signal chain.

I'd record some test tones, i.e. a sine sweep, and make sure you're not losing your mind as far as low-end loss. There is nothing euphoric about test tones; they're annoying and you can't "fall in the love with the sound" of beeeeeeeeeeeeeeeeeeeeeeeep... well, maybe the modular synth guys can

For what it's worth, headbump is a real thing, but I can't imagine a reasonably modern converter not capturing that today, even at 44.1kHz/16-bit.

100% I well serviced Revox machine is a thing of beauty, and in terms of calibration why leave it to chance when you can have more control and repeatable results?

A loopback test is taking a single cable out of your Audio Interface and back in to record just the effect of a roundtrip DA and AD. Then comparing the recorded audio to the original source - I often use a full mix for this. This will let you know how the Interface is sounding - I reckon it is likely just fine, but good to know for sure

Be sure to put this to a blind test - so you can rule out the psychological influence of using tape. The musicality to our conditioned minds is real, but you want to make sure by using only your ears in a blind test.

With respect, it sounds like you may be letting your mind overrule your ears

Not me and I do this every day.

Calibration isn't an issue because (A)....you like the sound as it is off the playback head & electronics....and

(B)...it's not like you've physically plopped the reel on someone else' tape recorder and decided it sucked on their machine.

So no-one besides me has a problem perfectly recapturing their 1/4" 15IPS bounces back to the box?

I'll drag the Cello to the cave the next time I'm there.. with the specs it boasts, nothing should be left to chance (freq response 10Hz to 70kHz, SNR over 120dB)

Or just run some tones man. This doesn't have to be a really big deal.

You can grab a tone generator app for free on your phone, plug it into a Y cable, record a 20Hz to 20kHz sine sweep directly to your DAW, see what's there and what isn't with any spectral analyzer (Voxengo Span is a good free one).

Now do the same thing, but hit your tape deck first, then record the playback into the DAW and compare.

Oh, that's not going to cut it if I want to get analytical about it. We have a 5 DVD instruction set (retails for 950 USD btw LMAO) at the office instructing how to properly analyse audio equipment, I'll skip netflix for a weekend, digest it all and dive in.. I'm going to want to test EVERYTHING. This is something I have been wanting to get to the bottom of for years now.. All I know is, electromagnetic audio transmission systems have some sort of inherent characteristics to their sound, and I want to know more about anything regarding their specifics. The more I know about it, the better. It goes beyond simple siloed measurements such as SNR and freq response, or we'd have perfect digital models of it already..

This. However it's very difficult if not impossible to match the tape deck's live output versus the digitized output within 0.1dB. That small difference can make things sound better in many different ways; not just level, when performing a double blind test.

That education will no doubt be valuable.

However, don't run before you can walk. Just learn how to do a simple calibration and maintenance cleaning of the machine - then spend as much time using the awesome machine with a really good tape formulation. I am sure that will be a big benefit.

I learned the most about tape machines from calibrating daily, trying out different calibration reference levels and recording to tape every working day for 6 or 7 years.

To use a driving analogy - you could read 100 books on driving, but driving 10,000 miles will make you a less dangerous individual on the roads.

Yes, everything you say makes sense. But to reiterate, I dont think I've even hit the tape at the optimal level yet (I am "aiming" the VUs as instructed by Lurssen Mastering's youtube videos), and already I like what its doing to my mixes. The same things happen to the program material that I am used to hearing at the office in my day job, and I've been transferring 1/4" tapes for 4 years now. I am not exactly a stranger to tape machines, only the recording side is new to me. Well that, and we use calibrated Studer A807MKII's at the office, not Revoxes. Some tapes are Telcom encoded, would like to own a 1RU telcom as well but it's still early days on the project cave side.. I don't really find low levels of tape hiss objectionable (not yet anyway)

I got a few reels of NOS BASF 911 & AGFA PEM 468. When those get worn out, I'll be buying more from recordingthemasters.com

Imho it is a tricky nut to crack.. you almost always loose a little bit something going in in my experience.. But with some converters less than others.. and some are utterly close..and sone do add something that is nice..

SPL does good stuff at a good price and do have sone excellent stuff in their hi end line.. but it might be that the crimson is not the best option for capturing the mix (or at least looks like you don’t like the results).

What you can do it trying to go in at different levels and see how the crimson reacts.. maybe doesn’t like to be slammed? I don’t have experience with it.. try to enter with a much lower level and boost it later in the digital realm with just a volume boost.. see what that gives?

believe it or not some people (who do edm/lounge/electronic stuff) do like the converters in the old Alesis Masterlink.. (they do add something indeed..if this is good or bad for you and your music/program I can’t say)..

Some of the very best AD I’ve heard is the Lavry Gold, but that is freaking expensive (and quite unique), and also the old pacific microsonics model 2.. they do have a “sound” for lack of better terms..

the Crane Song Hedd (or better said the Interstellar which is the AD version only of the Hedd), the Dangerous convert AD, the Acousence AD (I believe it’s the 191 model).. are all excellent, also not cheap but somewhat reasonably priced.

The Avid I/O 16x16 converters are actually pretty good for capturing a mix, as well as the prism ADA 8XR.

Unless you’re lucky and you like the way some old converter capture the mix, it is not very inexpensive solving this “issue”.. (despite in general terms the converters in 2024 are all pretty good, but capturing the program is not so an easy task, in my experience).

I hope this helps,



Cheu

as others already said: have you done a loopback recording yet? play a mix and record it directly on your ad.
easy thing and you will know what you are losing on the da/ad side.

some noticable degradation is totally in the cards with a 7 year old midfield converter.

how do you monitor from the tape machine? and what do you change then for recapturing?

I dont think the loopback test is the answer here. I have always been happy with how my Crimson sounded prior to this, and in fact remember it being my first audio interface where I could not discern any change in sound after conversion during my initial tests with it. Sources I typically used back then exhibited zero "tone suck", unlike my experiences with something like UA Apollo desktop boards, which did exhibit a bit of tone suck to my ears

I'm about to start binging on that 5 DVD testing course. I also installed my Cello to the project cave yesterday, and could hear a change straight away. Cello is maybe slightly faster than the Crimson, microdynamics and transients improved somewhat, although I'd need to conduct actual tests to be able to know for certain. If there is significant improvement and not just placebo, it should also translate to more "true to the source" captures of the Revox going forward..

It's also possible that my interconnections are at fault here. I have already devised a more optimal interconnection scheme for the Revox, I'll need to implement that as well before going further. I'll be using my Lake People Sym-Amp for converting all the unbalanced RCA I/O of the Revox to proper balanced XLRs, using 0,5m or 1,0m RCA cables

Good point about that "if all things equal, louder is always better" though. I need to make a listening test where I audition the tape and the capture, and deliberately gainstage the capture to be louder than the og tape source. If the capture sounds better when its louder, I can most likely write off the diffs as placebo

Oh man, dunno if yall have seen this video, but the two guys nodding to the things Mr Wolfe is saying, classic meme pack material right there

this post probably tool longer to write than doing a loopback test.

and then you would have known if converter sound ks anything you have to worry about or not.

don‘t ask for help if you don‘t want any. this is a waste of time.

Don't screw up.

Have your tape recorder calibrated today.

Otherwise, you are guaranteed to get poor performance.

Don't screw up.

Every piece of gear will change the sound somewhat, so yeh it will sound different just going through a thing. I’ve heard a lot of changes from tape going to digital, but being able to point to something non-esoteric and measurable would not be one of them. It’s usually just a sort of “glassy” quality from analog to digital, or a sound that seems to inexplicably make it sound more “boring” or something.

I think the people telling you to test w/ tones are trying to help you determine if there’s actually a frequency loss. Which if you do care, would be a good idea probably. Because if you’re saying there is an actual loss of low frequencies, then there is a problem. And I would put money on that problem being impedance-related if there is one. Not sure the impedances between your two pieces of gear, but this is something that I just recently learned can be a big deal with some older gear. Also not sure if the Revox is a -10 or +4 device, so you might have some operating level item to deal with.

That said, it’s only music and if it sounds good, it is good … you can fly blind and leave it to the cosmos and chance and things sometimes work out magically. My friend used a Tascam 388 and we both agreed that the “wrong” tape (an old red box Ampex, which was super out of alignment for this deck) actually sounded better than the normal RMGI the deck was likely set up for. But it was super murky and likely very over-biased.

BUT …

The more I learned about tape over the years, the more I understood how important calibration is. Calibration is changing your guitar strings and setting up your guitar. Yeh it might sound fine just grabbing it and going for it, but guaranteed it’s not as good as it could be. If it’s close enough, it may not matter. I would say multi-track calibration is less of a big deal since you’re gonna use EQ and mix anyway, etc. But a mix deck IMO really should be calibrated, at least initially to get it ballpark. It may drift a bit over time, but not likely too far.

The amount of bias is super important. I did some experiments once with overbiasing … biasing “cold” gives a bright, clear sound, going too far over loses detail and sounds like the “saturation” people talk about. But the idea what you are operating at a particular bias without even knowing what it is means that you have “saturation”, “gel” and “high EQ” knobs set randomly. Among other things.

Not that the points above have anything to do with the change after hitting converters. I’ve always used a 20-year old Sony CD recorder as my “converter”, and recently realized I was comparing the sound from the analog deck to the headphone out on the Sony. When I use the line outs with a stand-alone headphone amp, it actually sounds much closer to the analog. Lots of variables.

you mean the magic goes away?

well of course everybody has this problem because Digital Is Contamination. Everybody here at GS knows that.

Please. I work at a respectable Broadcaster. Everything there is predominantly digital and has been for decades. The systems there have been designed by people who know their stuff. I am merely a dillettante doing as I'm told. I have read enough of your posts to know that you are chronically butthurt by the ramblings of GS's many keyboard warriors, you can be at ease, I will not be fighting you.

I am just trying to understand why my ghetto rig at the prjocet cave gives subpar results vs what happens at the office. I know already I have lesser gear at my disposal. So is it my converters, my interfacing to the tape deck, or just placebo? Is what I'm trying to find out here..

Why would I be teaching myself how to use a 3,500 USD audio testing software if I was content simply doing an audio interface loopback test with white noise etc? I am genuinely interested in learning more about the issue, and if I learn more about doing proper audio testing in the process, thats a plus in my book. Learning proper methodology for making audio tests is something which oughta be very welcome in these circles, GS especially.

The low end changing issue I speak of is not that I experience rolling off of low end, like there would be LF cramping or something. The added bloom in the lowend my mixes get when recorded to tape diminishes when recaptured. This could very well be an impedance thing, phase shift, or something else entirely. I doubt it would be just simple LF cramping. My playback system only goes to 40Hz, and even a crappy AD converter can handle down to 20Hz, surely even a crap AD would at least capture all the lows my playback system is capable of making audible for me?

So this might be related to what I am expereienceing as well

I am still learning the DVDs so inconclusive ATM, but I was able to set up an A/B switching between the analog and post-converter program material. After adjusting for level differences, the difference (while still present somehow) is now agreeable enough for my project cave use. Set 96k Cello with 0dB preamp gain, and having the Sym-Amp between the source seems to reduce this, "glassiness" so as not to be objectionable to the material IMHO

Key ended up being the balanced insert sends of the Cello, whjch send the signal pre AD.

I am still messing something up, I'll figure it out eventually..

How do you know playback through the UA D/A is within 0.1dB of the playback directly from the deck itself (not through a D/A)? A larger difference than that has been known to be perceived as <name your favorite audio adjectives here> in thorough double blind testing. Personally, I've gotten the levels close enough to where I have not perceived a difference between playing vinyl directly back just after it's been recorded through both Lavry, RME, and even Steinberg converters. You have to get rid of all of the variables that will surely make your brain play tricks on you.

Yes, it all sounds the same always, everything else is just misjudged levels when A/Bing.. yet there are measurable differences in converters.. go figure. I am clearly just insane and I am imaging everything that comes out of the speakers. I should be just watching spectral graphs with the monitors turned off

No reason to get uptight and defensive: think of a measurement tool or a visual display as just a confirmation of what your ears are telling you... that is, if you're not afraid to find out the truth...

Ok, from this point on I will declare any perceived differences in sound quality, regardless of topic, to be a mismatched level in A/B testing