SQPB - what is it?

[DVtyro]

I mean, I know what SQPB does: plays SVHS tapes at regular VHS quality, does not record SVHS. But what exactly is it?

Is it, basically, SVHS VCR that is deprived of recording SVHS? Does "VHS quality" simply mean that the video is output via composite, not SVideo? So, if I use a true SVHS VCR and output via composite, is it "VHS quality"?

If it is indeed an SVHS VCR that was limited to playback only, is it any different from proper SVHS VCR aside of missing SVideo output? Does recording SVHS require extra hardware compared to recording VHS and playing back SVHS?

If it is indeed a neutered SVHS, why was this done? Just to create two price points for VHS and SVHS? I think this was a mistake, I think that JVC should have completely switched to SVHS in 1987. Was SVHS hardware significantly more expensive than VHS? As far as I understand, the biggest difference was in tape quality to provide wider bandwidth.

Or is it more or less regular VHS somehow enhanced to play SVHS tapes? In this case I am not sure why regular VHS machines could not do it.

On a side note, it seems that Super Beta was a reasonable compromise, having the resolution almost like broadcast TV yet backwards compatible with most older machines. Too bad that JVC decided to outclass Super Beta, creating an incompatible format. Or, it should have given more bandwidth to chrominance, say 330-350 lines of luminance and 80-100 lines of chrominance, it would be an all-around better format, much closer to Betacam, which, I believe, has 330 luminance / 120 chrominance resolution. It seems that VCR manufacturers were blinded by luminance resolution only, despite that most people had color TVs in 1980s.

[redk9258]

Here's a tread about it..
https://www.tapeheads.net/threads/wa...an-svhs.93816/

Seems like a VCR that can play higher quality tapes than a normal VCR could.

JVC could not have just switched to S-VHS in 1987 because there was a huge market for VHS. Since the machines cost more, it may have killed the whole VHS format. If people wanted the higher quality, it was available. Remember, back then almost nobody cared about picture quality. Most recorded in 6 hour mode! Also CRT TVs (mostly 27" or under) seem a lot more forgiving for picture quality than your big 65+" flat screen!

[DVtyro]

Originally Posted by redk9258

Seems like a VCR that can play higher quality tapes than a normal VCR could.

I am looking for a bit more technical answer, thanks.

[Dude111]

I havent ever heard of SQPB..

I assume it means

Superior Quality Play back

But to be honest my reg VCR looks quite beautiful to me.......

[dishdude]

Originally Posted by Dude111

I havent ever heard of SQPB..

I assume it means

Superior Quality Play back

But to be honest my reg VCR looks quite beautiful to me.......

Super VHS Quasi Playback.

Allowed regular VHS machines to play back tapes recorded on S-VHS.

[Dude111]

Ahhhhh <<>> Mine will play SVHS but I assume its standard quality........

[DVtyro]

No one can explain how does SQPB actually work?

[dishdude]

Originally Posted by DVtyro

No one can explain how does SQPB actually work?

It was nothing but an advanced chip and circuit (by regular VHS standards) that could read an SVHS recording and output it at standard VHS resolution. There was nothing special about it.

[DVtyro]

Originally Posted by dishdude

It was nothing but an advanced chip and circuit (by regular VHS standards) that could read an SVHS recording and output it at standard VHS resolution. There was nothing special about it.

How much different / less expensive was it compared to proper SVHS if I cared only about playback? Would this chip, feeding Y/C video into SVideo jack deliver practically the same quality as SVHS VCR? Were there, to your knowledge, SQPB machines with SVideo output?

[dishdude]

Originally Posted by DVtyro

How much different / less expensive was it compared to proper SVHS if I cared only about playback? Would this chip, feeding Y/C video into SVideo jack deliver practically the same quality as SVHS VCR? Were there, to your knowledge, SQPB machines with SVideo output?

I've never seen an SQPB machine with an S-Video output (not counting VHS/DVD combos, but they would only output the DVD side over S-Video). Also all the machines I've ever seen were clear that they provided S-VHS playback functionality at VHS quality. If you're looking for S-VHS quality playback, you need an S-VHS machine.

JVC really started the push for SQPB when Sony offered Hi8 Camcorders, this allowed them to offer S-VHS-C camcorders to compete without the need for people to buy an expensive S-VHS VCR for playback.

[Electronic M]

Originally Posted by dishdude

I've never seen an SQPB machine with an S-Video output (not counting VHS/DVD combos, but they would only output the DVD side over S-Video). Also all the machines I've ever seen were clear that they provided S-VHS playback functionality at VHS quality. If you're looking for S-VHS quality playback, you need an S-VHS machine.

JVC really started the push for SQPB when Sony offered Hi8 Camcorders, this allowed them to offer S-VHS-C camcorders to compete without the need for people to buy an expensive S-VHS VCR for playback.

My Toshiba D-VR5 has SQPB and will send the tapes output through S-video, it also has S-video input and will record to VHS or DVD from that input. It'll also playback VHS through it's HDMI output too.

[ChrisW6ATV]

Others may know better for sure, but essentially SQPB is a circuit that lets the VCR read the Super-VHS luma recording at its correct center frequency, but without the expanded bandwidth (higher resolution).

SuperBeta VCRs did this same function right from the start, without needing a separate switch. But, SuperBeta was less of an improvement/change compared to Super VHS.

[DVtyro]

From "VCR troubleshooting & repair" by Capelo, Gregory R; Brenner, Robert C

Presently, only metal heads can be used to record on metal tape. Ferrite heads can play back a prerecorded signal from metal tape, but cannot record on the metal tape.

This does not apply to SVHS though, as SVHS tape is cobalt-doped ferric tape (BASF also offered chrome tape), so it is basically Type II tape in audiocassette terms. It it is known that cheap audiocassette recorders meant for Type I tape only did crappy recordings when Type II tape was used.

[ARC Tech-109]

Has to do with the actual magnetic energy and saturation of the head material itself as ferrite saturates at far lower levels than it takes to actually imprint a metal based tape. Cassette technology also requires a far higher bias and signal drive to record on a metal tape be it ME or MP formulation.