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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 20th Nov 2020, 12:06 pm   #1
Martin Bush
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Default 8 track sibilance

Hi all

I am now enjoying my 8 track player and refurbished cartridges.

One thing I am interested in is finding out why some tracks suffer from sibilance. I may have the term wrong, but what I am trying to describe is a sort of distortion that happens in certain circumstances.

A good example is the Carpenters' song Yesterday Once More where she sings "Every Sha La La La..."

The "Sh" is quite distorted and, for want of a better phrase, "breezy".

Is this simply a problem with the pre recorded tape or is there some fix I could investigate?

My machine came from someone who looked after it and knows about servicing, so I don't think there is a fault with it.

I have a 10cc one on the way and I will be interested to see how I'm not in Love fares.

I know that there's varying views on 8 tracks - I know I'm not going to be having a hifi listening experience, but I am interested in what I am hearing.

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Old 20th Nov 2020, 2:08 pm   #2
Edward Huggins
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Default Re: 8 track sibilance

Well at 3 3/4 ips you should get a quite good sound. Assume you've cleaned the heads so it's liable to be the old pre-rec tape. Is it shedding?
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Old 20th Nov 2020, 2:17 pm   #3
Ted Kendall
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Default Re: 8 track sibilance

What you are hearing is probably "HF crushing", which happens to some extent at any domestic tape speed - the frequency response deteriorates at high levels, which is why bias and EQ adjustment is generally done at 10 or 20dB below peak level. The usual practice was to put the signal onto pre-recorded tapes pretty hard, too. Add the characteristic Carpenters vocal sound - bright and close - and there you are. In extremis, you may hear LF intermodulation products under these peaks.
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Old 20th Nov 2020, 2:30 pm   #4
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Default Re: 8 track sibilance

If it's any help, Yesterday Once more (the sha la la multitracked bit) sounds distorted on my vinyl copy as well, the mics sound overloaded.
It's possible it's been remastered for later recordings.
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Old 20th Nov 2020, 2:58 pm   #5
Martin Bush
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Default Re: 8 track sibilance

@Edward_Huggins - as far as I know it is not shedding. The tape seemed in quite normal condition. The sound occurs in quite specific parts of songs and that one was the one I remembered when I did my post. Overall the sound IS quite good. There's a bit of dropout and so on which I am putting down to how it's been stored/ looked after over the years.

Ted and Kevin - what you say is very interesting. I will see how other tapes fare. My copy of 10cc How Dare You also suffers from this problem - again it seems to relate to the characteristics of the music. I have the album on LP so will listen closely to it and see if I can detect any distortion.

I have a John Lennon one on the way so I wonder how "All we are SSSaying iSS give peaccccce a chancccce" will sound.
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Old 20th Nov 2020, 4:01 pm   #6
TIMTAPE
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Default Re: 8 track sibilance

To my ears all The Carpenters albums were produced to a very high standard. Just listen to the CD rereleases. At their best 8 track carts sounded fine for casual listening but a lot depended on how well the tape duplication plants maintained and aligned their high speed duplication equipment. As with pre recorded cassettes the quality could vary a lot but overall the quality probably got better over the years. "Sibilance" could result from a tech noticing the highs starting to droop on copies and doing a short cut by merely boosting the highs at the record stage when often the proper fix was to relap or replace record heads and rebias, but that took more time, required more skill and cost more.

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Old 20th Nov 2020, 4:29 pm   #7
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Default Re: 8 track sibilance

Hello,
What’s the finish like on the capstan, it should have a dull coating and not polished so it may be slipping. I have the same cartridge playing on a cheap player and it seems ok to me.
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Old 20th Nov 2020, 4:33 pm   #8
Martin Bush
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Default Re: 8 track sibilance

Inside the machine you mean (just checking I am understanding correctly)? I will need to open it up to look.
The pinch roller in the cart is fine - I cleaned and inspected it when I refurbed the cart itself.

Another idea, if it's not the tape itself, is whether the pressure pads I have used are deep enough. The originals were foam/ sponge and had turned to dust. I replaced them with felt pads which seem good quality but may not be thick/ deep enough.

I have 10cc How Dare You on now and it's perfectly listenable bar the odd bit of "essing".
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Old 20th Nov 2020, 4:53 pm   #9
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Default Re: 8 track sibilance

Hello,
Yes look through the front and the silver bar on the right in the vertical housing is the capstan. Top and bottom will be shiny but the bit which the roller pinches the tape to should have a rougher dull finish. I think it is an etching of some sort to give the required grip. I have just looked at mine a cheap Thorpe Grenville and it is noticeable but it works.
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Old 20th Nov 2020, 5:07 pm   #10
Ted Kendall
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Default Re: 8 track sibilance

Quote:
Originally Posted by john.north View Post
I have the same cartridge playing on a cheap player and it seems ok to me.
Trouble is, as Tim alludes, the quality of pre-recorded tapes was often shockingly variable, both between slaves on the same run and between runs, so it could be a sample fault on the particular tape.
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Old 20th Nov 2020, 5:16 pm   #11
Martin Bush
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Default Re: 8 track sibilance

I have had a look and I think it's OK.

See if you can make it out here...

The light brown line down the head is a reflection I think rather than something stuck on it. I had to stick my phone near the slot and hope for the best

@Ted_Kendall this Carpenters one is particularly bad in places. Not unlistenable as I can withstand a fair bit of noise, but it's certainly noisy. I read that 8 Track content was recorded onto the carts - not sure of that's correct but seems a sensible explanation for the variable quality.

I have to say that none of this had put me off so far. I've some more tapes coming and I am enjoying the listening experience. You get to know the songs as they keep coming round (and I've not got sick of them yet).
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Old 20th Nov 2020, 5:36 pm   #12
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Default Re: 8 track sibilance

Hello,
Yes you can see the etching more noticeable above and below where the tape runs but it is still there where the tape runs, might respond to a clean with some ipa. Also have you replaced the belt and cleaned the flywheel? Mine is 40+ years old and was taking ages to get up to speed. I got one from gb audio but I think Sid at Cricklewood electronics would be able to source one.
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Old 20th Nov 2020, 5:39 pm   #13
Ted Kendall
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Default Re: 8 track sibilance

Quote:
Originally Posted by Martin Bush View Post
I read that 8 Track content was recorded onto the carts - not sure of that's correct but seems a sensible explanation for the variable quality.
High speed duplication was established practice long before the cart arrived - and achieving consistency with the level of QC possible at a sensible retail price is explanation enough, believe me. Far more likely that cassette practice was broadly followed, with duplicated pancakes having individual programmes parted off and loaded into cartridges by semi-automatic machines.
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Old 20th Nov 2020, 5:44 pm   #14
Martin Bush
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Default Re: 8 track sibilance

Quote:
Originally Posted by john.north View Post
Hello,
Also have you replaced the belt and cleaned the flywheel? Mine is 40+ years old and was taking ages to get up to speed.
John.
I got the deck from ebay but the seller said he had serviced it and replaced the belt. I believe him as he is a member either here or one of the similar UK vintage forums - we've exchanged some good messages on ebay and you get to know the kind of people you trust from the answers you get to your questions.

Speed wise it's instant, heads shift tracks nicely and it is in very good cosmetic condition.

I will see how the next few tapes perform (a couple of 10cc, a John Lennon and a Curtis Mayfield if anyone is interested!)
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Old 20th Nov 2020, 7:15 pm   #15
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Default Re: 8 track sibilance

Sometimes pre-emphasis in the form of Dolby NR was used but I can't remember if
that was a feature of 8-track- if so reduction of treble may help.
As mentioned problems arise from high speed duplication which can include azimuth error - noticeable if you listen in mono (L+R)
If you obtain a recorder, the recordings with a good tape will sound better than a cassette.
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Old 20th Nov 2020, 7:18 pm   #16
Martin Bush
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Default Re: 8 track sibilance

@Restoration73 thats where i may be heading... but i am trying to resist!
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Old 20th Nov 2020, 11:40 pm   #17
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Default Re: 8 track sibilance

Re: post 7. I don't see how a dirty capstan would produce sibilance, or have I missed something?

In my experience this effect happens on tape with excessive record level and/or incorrect bias, as highlighted by TIMTAPE. Last year I recorded some language tapes on a Tandberg cassette deck which I wasn't familiar with. I must have had the level too high as there was terrible sibilance on some of the recordings.

I don't think that deck liked the modern TDK D cassettes I was using, either. most Euoropean decks seem to have been set up for BASF FE tape, which has totally different bias requirements than TDK or Sony.

As has also been said, at the end of the day it's pre-recorded consumer tape, which has always been a bit hit and miss. I was sure I had a 45 rpm copy of 'Yesterday Once More' and tried to dig it out out of curiosity, but I just came up with 'Only yesterday' which was a different song!
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Old 21st Nov 2020, 6:32 pm   #18
Martin Bush
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Default Re: 8 track sibilance

I may have found the problem...

I pressed a button on my amp which i was certain only applied to the tuner (its a receiver amp). Its now playing pretty faultlessly.

The button in question is the 'stereo/ muting' one which i was convinced was just for the FM tuner.

Deceptive Bends is now playing in almost hifi quality with no sibilance.

Thank you all for your help and i apologise for my incompetence. That said, its a lesson learnt!
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Old 21st Nov 2020, 11:50 pm   #19
TIMTAPE
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Default Re: 8 track sibilance

Ah the old summed to mono problem. Cassettes and 8 tracks are notorious for poor timing between stereo tracks. Normally they should only be played in stereo as designed. But the sonic effect of summing to mono wouldnt normally be be described as "sibilance". This is where supplying us with an actual sample file of what you are hearing can greatly speed up the diagnosis.

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Old 22nd Nov 2020, 1:02 am   #20
Martin Bush
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Default Re: 8 track sibilance

I will have a go in the coming days when i have time to properly listen and note all the settings and get a decent recording to llustrate what i am experiencing.

I said sibilance as it was very prominent on words with an S when i first noticed it. In reality perhaps it happens at other points too.

I want to first confirm that however i have the amp set up has solved the sound issue. Once ive done that i will take proper notes and report back. The last tape i listened to, having changed the setting, sounded very good to me...
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