18 bits recording. How to put in practice?

Hi DCC lovers,

for my first message, i’ll ask if anyone knows how to put in practice the 18 bits recording.
Does anyone have experience in successful recording of materials in 18 bits mode? What was the source and how did you feed the recorder?

Thanks a lot in advance for your lights.

And happy new year :slight_smile:


Feeding 24 bits will work, according to this tapeheads thread. To be honest, I don’t think it would create an audible difference given that normally 16 bit is used. If you want to continue anyways, I suggest getting some USB S/PDIF output device with ASIO support and using the free software Foobar2000 to play i.e. a suitable FLAC from some highres shop.

18 bit recording or even 20 bit (Victor 919), can only be achieved if you are using the analog input of a compatible recorder. (730/dc8/909//951/170/175/dr9)

Digital connections only allow 16 bit.


Oh, okay. At some point I will write a new PASC encoder which will support this feature, but this is far from my top priority.

@drdcc Could you record something analog in 18 and 20 bits and extract it via PC link? Could even be analog garbage like noise, but it should utilize all the bits.

When using the pc-link cable it is 16 bit output.

So if you copy something 18 bit on the PC and on another tape it will be 16 bit? I assumed it would only be a limit of the wav to pasc encoder.

Yes it will only be 16 bit.

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Thanks for the replies.
So all the fuss Philips made on for 18 or 20 bits recording functionnality was only for… analog recordings?

As far as we know, yes. I am not sure about the Victor ZDV919 as we have no technical specs yet.
We actually have various tapes here at the dccmuseum that are recorded in 16 and 18 bit (same title naturally). We had quite a few audiophiles listen to them on different high end sets and performed a blind test. It was never conclusive. We are either to old (lol) or your hearing needs to be extremely good. There are documented tests from audio magazines that did hear the difference and used the same tapes we did.

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Last year in Holland, we did test with multiple recorders and multiple recordings.
Analoog seems t be the only way for a 18bit recording.
Digitaal form a dvd-audio or Blu-ray output is the down sampling of the player. This is max 48khz and 24bit.
The output bit rate is not depending on the type of recording but type of recorder.

For example a prerecorded 16bit playback on a 18bit recorder puts output 18bits (pasc remaps the depth). And an analogue recording on 18bit recorder, and playback on 16bit recorder wil be 16bit.

The idea is to make together with DR DCC a video about this, with visual results.


I’m already waiting for this video :slight_smile:

Thanks everyone for your feedback.

Hi I agree with Ralf, you are only able to make 18bit recording while feeding a analog source
into a rca input. 18bit capable unit like the Philips DCC951 or DCC 730 in my experience. Ist gen’s are limited to 16bit resolution based on their on board ADC.

I didn’t see this thread until now for some reason.

The previous answers are wrong: the third generation recorders (stationary recorders DCC-951, DCC-730, portable DCC-130, DCC-170 and DCC-175, mini-system FW-68, unreleased DCC-771 double-deck) all use the SAA2003 / SAA2013 chips for PASC encoding/decoding, which are capable of handling 18 bits on their input and output. They also have ADC and DAC chips that are 18-bit compatible, and digital I/O chips that are 18 bit compatible such as the TDA1315.

So if you record a tape with a third gen recorder, the PASC data is based on 18 bit samples, so you could say it’s 4 times as accurate. Obviously, if your source is a CD player, the lowest two bits of the 18 bit input samples are always zero because CD only has 16 bits of resolution. But an 18 bit (or more) SPDIF source should result in a recording of 18 bits of audio.

When using one of those 18-bit decks to play a tape, the PASC decoders will decode the data on tape to an 18-bit signal too. Most likely, they will always generate an 18 bit output signal even for cassettes that were recorded from a CD, and even for cassettes that were recorded with 16 bit recorders.

In those cases (where a tape recorded from 16 bit source and/or recorded on a 16 bit recorder), the lowest bits will just contain noise (but don’t worry: the two least significant bits add less than -97dB of signal). For 18-bit recordings played on an 18-bit machine, the output (digital or analog) should be a psychoacoustically accurate representation of the input.


What is the role Of sampling rate indicator in recordings 44.1 .48.96khz
Does this indicator make difference in music quality

44.1 vs 48 khz sample rate is a historic discussion, converting can result in quality loss, so both is supported. 96 khz is not supported by DCC as far as I know.

Yes i understand that 96khz is not supported by dcc and we can use 48khz as max bitrate all i wonder if this make difrence in PCM system 24 bits vs16 bits
41.1 vs96 khz if source is 16 bit and then like Jack explain extra bits are simply dither noise for microprcesor and upsumping to higher rate can distort music i wuld like to see in future recodings in high quality and then with high quality source is exelent final product like dcc tape

Excuse the off topic, as this is a rather theoretical discussion, I will explain it.

Yes, it does. 24bit/96 kHz is a well known combo which improves quality at least for editing. There’s a long standing debate over whether you can hear a difference, I don’t think so. You can find it mostly in studios or in special online shops as FLAC. Physical consumer mediums for that (can also carry surround) are rare and obscure: DVD-Audio, SACD and Blu-Ray Audio. Most players of these formats will see a disc.

There are also some compressed High Res formats, which kind of defeats the point.

You absolutely right I don’t hear difference sometimes ago I took test and to my ear best sounding music was mp3 320kbps this
was my choice with other formats
But I must say that I have many hdcd and there is different dynamic and I can hear this thx

This is because HDCD and other High Res formats tend to be not affected by the Loudness War and closer to studio masters. By the way HDCD is even more controversial than DCC was, because it claims to be CD compatible, but with a reduced audio quality and when playing with an HDCD player it’s still a lossy compression.

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@Jac is correct. Feeding the correct signal into the spdif input on a 3rd gen will create a 48kHz signal and that could be 18bit depending on the source.

@Jorn and Krzyzstof have confirmed this.

We have tested Jac’s test solution for the dcc175 successfully this week. The breakthrough is that depending on the master, the next release done by the dccmuseum could be the very first commercial release on 48kHz 18 bit (or higher).``

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