Mark’s CT-F850 arrived- some questions…

[MarkWComer]

Looks beautiful, and it’s mechanically sound, but two minor issues:
The input control is a L|R coaxial pot, but they’re frozen together. DeOxit will fix this? I dare not use penetrating oil, of course…
I made a 3kHz test tone in Audacity, with tape | source switched to source, input shows balanced input, but when set to tape, L appears to be 3db lower. Neither of these are really terrible issues, but didn’t I tell you’s I was a picky bastard?
Will download the user and service manuals and see what kind of fiddling I can do.

Take note of my bias setting for this tape: -5 on the scale. I recorded some music while monitoring the tape. At -5 on this scale the sound was much better for the highs. Do others who use this tape notice this? Sounds really muddy until I make this adjustment.

 

[mr_rye89]

Yeah you tweak the bias so that the recording sounds as close to the source as possible, or go further until it sounds better to your ears if you please. Is it still 3 db off playing a pre recorded tape?

also the deck should have internal bias adjust pots.

 

[MarkWComer]

Yeah you tweak the bias so that the recording sounds as close to the source as possible, or go further until it sounds better to your ears if you please. Is it still 3 db off playing a pre recorded tape?

also the deck should have internal bias adjust pots.

I don’t have any pre recorded tapes.

I removed the cover (naturally…) and saw all the adjustment pots, hesitate to fiddle with those because tape characteristics will vary between manufacturers. Of course, if I’m consistently recording with that bias setting with other brands I’ll tweak it. TDK and Maxell seem to be the dominant brands so I’ll get a sample of each in order to make that decision.

It’s 41 years old, so get a service manual!

 

[Wheel-right]

Nice looking piece Mark, hope you get it all squared up and enjoy the ancient art of cassette tapes. Always have a pencil handy.

 

[mr_rye89]

Hard to tell if it’s a record or playback problem otherwise……could be that froze up input pot or if your output pot is scratchy…….do Pioneers of this vintage have 2sc458 transistors in em?

 

[MarkWComer]

No 2SC458 shown in the service manual.

Level meters show a balanced stereo signal with 3kHz test tone in “source” monitor mode, the difference shows in “tape” monitor mode. I think this shows a discrepancy in the amount of signal presented to the tape head during record.

Will try a small blast of DeOxit on the pot shaft to see if it will unfreeze. Penetrating oil might be risky.

 

[Elite-ist]

Try a different blank cassette - I'm not sure what ATR loaded into their shells. Look for an 80's Maxell or TDK Type I or II.

Nando.

 

[MarkWComer]

Try a different blank cassette - I'm not sure what ATR loaded into their shells. Look for an 80's Maxell or TDK Type I or II.

Nando.

Is the left channel at the edge of the tape? Shouldn’t make a difference, just curious…

I have a TDK D90 blank, but playtime is over for now and I’ll try tomorrow.

Looking at the ATR tape, the oxide doesn’t appear to be uniform- splotchy and uneven. No audible variance, no dropouts or volume bursts (I connected my iPod and recorded some audio- not just the test tone), just looked bad. If it were movie film I’d bitch a blue streak for uneven exposure.

 

[Elite-ist]

Yes, I believe the left channel is on each side of the tape and the right channel is on the inside.

Nando.

 

[Elite-ist]

Don't use that ATR cassette if the tape surface looks irregular/bumpy. It can erode a head with repeated use.

Nando.

 

[MarkWComer]

Don't use that ATR cassette if the tape surface looks irregular/bumpy. It can erode a head with repeated use.

Nando.

Not bumpy, but splotchy. Oxide leprosy?
Left channel is at the edges.

 

[pioneercollector]

I agree with Nando, grab a nice TDK AD or similar from the 80's.... give that a swirl before going in.

The deck does look mighty purdy!

PC

 

[MarkWComer]

The deck does look mighty purdy!

One complaint- no compartment door to keep dust out. I might keep a tape in to block the dust, the head cover just doesn’t seem to be sufficient.

 

[Elite-ist]

You would be better off just using the hinged head cover and not keeping a cassette inserted in the well. Never had an issue with dust in the tape path in any of my open-well cassette decks - with the exception of one - Revox B 215. I remedied that by finally getting my hands on an original well-cover for it a few weeks back.



Nando.

 

[J!m]

If you want it gone through (I know Sam is swamped and may not take a Pioneer in if he wasn't- not sure)

Scott Grammer in TN did a fantastic job on my Sony D5-M. He was suggested by Bob Boyer. He has no trouble with high-quality old decks, but won't touch my Panasonic boom box...

PM me if you'd like his number to chat. He'll set up the bias for the tapes of your choosing of course. Plus head alignment, transport overhaul etc. I'd send any non- Teac/Tascam decks to him without reservation. (pricing is quite reasonable too).

 

[MarkWComer]

If you want it gone through (I know Sam is swamped and may not take a Pioneer in if he wasn't- not sure)

Scott Grammer in TN did a fantastic job on my Sony D5-M. He was suggested by Bob Boyer. He has no trouble with high-quality old decks, but won't touch my Panasonic boom box...

PM me if you'd like his number to chat. He'll set up the bias for the tapes of your choosing of course. Plus head alignment, transport overhaul etc. I'd send any non- Teac/Tascam decks to him without reservation. (pricing is quite reasonable too).

I really didn’t get to fiddle with it until just today, so for S&G I recorded two of my “frequent flyer” LPs on one of those Warmalt cheapies, and it seemed to be in balance pretty well. Perhaps my first checkout was on something that was stronger on the R channel than the L. Didn’t account for that pesky “stereo” crap everyone’s raving about. My Polyrock albums switch dominance from L to R frequently, and the VU meters responded correctly.

So, yeh- she’s a good girl!

 

[Elite-ist]

Did you adjust the bias control while doing a test recording to see how close of a copy to the source you were getting, while monitoring the recording? I'm interested where the bias control worked best - either positive or negative from the centre detent position.

Nando.

 

[MarkWComer]

Did you adjust the bias control while doing a test recording to see how close of a copy to the source you were getting, while monitoring the recording? I'm interested where the bias control worked best - either positive or negative from the centre detent position.

Nando.

Full minus on the bias control had the best HF clarity, came pretty dang close to source with A/B switching between source/tape. This is why I insist on three heads. The Warmalt tapes seem to match the ATR tapes in this respect.

 

[J!m]

That’s great!

if you get the internal bias set for those tapes you’ll have more range of adjustments to fine tune each lot.

 

[Elite-ist]

I wouldn't be adjusting anything internally for the Walmart cassettes until you've found an older formulation which is an economical alternative cassette you can buy in bulk. You have to up your price point to the $5-$7 per cassette range, as a starting point. Give your deck a fighting chance to do what its supposed to do.

Nando.