Tascam 244, picked up today

Okay, checked the manual again!!!

There is a dbx bypass for playback amp checks/adjustments, but it's not this lonely connector. It's J203/J204, which you must remove the plugs (P203/P204) and then short some pins together, a pair for each channel.

Something funny about the "formal" adjustment procedures, from time to time: If it says 'do this/do that/measure here', often times it's really most efficacious to forget that and "watch the meters". If you've done the preliminary setup in calibrating the meters, this is effective and for all intents and purpose your resulting 'output voltage' should line up in spec.

I'll be honest enough to acknowledge that I've not read nor followed all the formal procedures for line-up of these devices. A lot of it can be more intuitive than what's in the manual. How many people on this site even have the 244 Service Manual, or would know or care to distinguish the difference?

Note: I could be all f'd up and wrong about this, but if you override the dbx for record repro alignment, then you'll have to also adjust the dbx encode/decode circuits. Alt., if you do record/repro with the dbx on, no doubt you're assuming the dbx is all up to snuff, but given that assumption, it's like one stop shopping. You'll never be able to disengage the dbx in normal use, so checking record/repro with dbx bypassed is moot. As long as your NR is effective, transparent and not pumping, you're good to go! That's IMO, & YMMV.

I assume some more experienced "pro" tech or engineer will hop on here and point out where I'm wrong, and why.

Next time I have opportunity to line up a 244, which may be soon, I'll try doing it more "by the book", and see what I get. However, I do get a dubious feeling about shorting pins together, for any purpose. Too many things can go wrong, (eh Cory?) ;)

:spank::eek:;)

PS: For the guy (forget which post or thread) who has "dbx pumping", (just above?), of course I'd recommend lining everything up exactly by the book, including the dbx. That's an audible anomaly in the dbx that has to be tweaked out. The fact of life with electronics is they can drift out of spec over time, and need to be lined back up.
 
Yeah, the DBX pumping was slightly annoying but I can deal with it for now, I'm sure there are going to be other things that creep up while I'm doing some test recordings. I'll be spending some more time with it soon enough.
 
Sorry man,...

my attention span can be incredibly small sometimes!
:facepalm:
Hopefully you won't find any more nits with the 244. In general it's a really great unit!
:spank::eek:;)
 
What is dbx pumping?

how do i turn the dbx on and off on the 244?
 
...

It's an odd, fizzy kind of sound that envelopes every note on the recorded track, especially with high gain transients, like from a drum machine or bass guitar.

The dbx NR is on full time, not switchable for on/off.
:spank::eek:;)
 
The thing I'm wondering about is, if I'm getting the enveloped-hiss around all my notes, but I'm recording in and playing back well below 0, the DBX has still kicked in I guess no matter what level it's set to.. I'm sure it gets worse and "pumps" once you exceed the 0vu level, which I have seen on my 388, but never with this nasty fuzzy hiss encompassing all notes. If it's pretty certain we are talking about a DBX issue, then where would I find the calibration for it, service manual?
 
Yes...

You need the Service manual,... (test tape, sig-gen, dvm, scope,... etc.)
Tascam Parts will sell you a reprint of the 244 Service Manual.
:spank::eek:;)
 
I have a 244 that I bought back in 84 or 85. I know from experience that if those two belts are shot then you will more than likely need to replace the idler tires also. You can get them on ebay as well as the belts. I have never had any problems with dbx pump on my 244.
 
Yeah I already replaced the idler tires with o-rings from home Depot, they work just fine. I don't know that the DBX is pumping so much, but there is an enveloped hiss encapsulating each note on tape so I still believe it's dbx related.
 
Q:...

How is the record/repro response, as far as levels?

If you hit it with a test signal at a given level, does it give the same level back to you?

My train of thought ATM is that if it's a gross level incongruence, might upset the dbx.

Of course, if you find the record/repro levels are out of whack, an alignment tape, etc., will be required anyway.

:spank::eek:;)
 
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Dave,
I'll have to check again and see; I just kinda dove into it the first couple days and started tracking stuff on it to test it out. Typical impatience.
 
WhinyLittleRunt said:
Yeah I already replaced the idler tires with o-rings from home Depot, they work just fine.
Click to expand...
I just read through all the post again and realized that you had said in an earlier post that you had replaced the idler tires. I don't know how I missed that. I hope that you have a lot of fun with your new 244.
 
Man I'm glad this thread is here... Reel Person: I'm having volume discrepancies between tracks on my 244, especially tracks 2 and 4 seem much quieter than 1 and 3 on playback. I recorded a constant tone at same volume to all 4 tracks. Just to make sure, I played the tape in my 424 and the same volume discrepancies were there so I think I can rule out the playback amp. So I want to try and tweak the Rec Amp. I've located the Rec Amp PCB, and see the labelling TP1, TP2, TP3, TP4... corresponding to the tracks I suppose, but its not clear which little dial controls the Rec Amp level. Would you happen to know the label (e.g. VR01 or L401 for track 1?) Would really appreciate it. I should get a service manual one of these days I know....

And also is there any reason why its wrong to tweak the Playback or Rec Amp level if there are volume discrepancies? I tweaked the playback amp on my 424 for track 4 after observing playback volume discrepancy and haven't had any thing explode in my face yet, in fact I'm really satisfied with the result as before having a bum track 4 was a real downer. My gut tells me that the REAL problem (the reason why a track would lose volume over time) is bias drifting out of spec. But calibration tapes are just way to expensive and the biasing/alignment process seems pretty involved, considering you can just buy another 4 track for cheap. Just doesn't really seem worth it to go through all that trouble when such an easy alternative exists... So can anyone tell me if messing with the rec/playback amps does any serious harm to the machine?
 
...

The Playback Amp level is usually set to a standard calibration tape. Without that you're kind of all over the place, but unless you swap tapes between the machines it's not a huge issue.

The Record Amp card is the one in the "can".
Record Amp:
Track 1: VR01
Track 2: VR02
Track 3: VR03
Track 4: VR04

The L inductor components are for adjusting bias & probably shouldn't be messed with unless you have a proper test equipment setup.

The formal procedure for Rec/PB Amp adjustment details disconnecting the dbx PCB and jumpering the connector pins together to bypass that open circuit, then going thru and adjusting the dbx after that, but I think unless you're having problems with the dbx encode/decode you can probably get away without doing this. The caveat here is if your PB Amp circuit is not set to standard, then your adjustments all get more dubious down the chain. YMMV.
 
A Reel Person said:
The Playback Amp level is usually set to a standard calibration tape. Without that you're kind of all over the place, but unless you swap tapes between the machines it's not a huge issue.
Click to expand...

Exactly, I don't plan to be swapping tapes around, it seems much more valuable to me to have each track within the same unit to be at the same rec/playback level than for tapes to be compatible across machines.

I'm seeing the "REC AMPL PCB" in the "can" but the V components are labeled VR01, VR21, VR41, VR61 on that PCB. I'm assuming these correspond the track 1, 2, 3, 4 respectively, but I'm not seeing the VR01...02...03....04 as you say on that PCB.

I really appreciate your help nonetheless.

*Update* I went ahead and adjusted VR21 and VR61, and track 2 and track 4 Rec vol/output is much healthier now, thanks Reel.
 
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Seriously!

There's a misprint in the service manual & I got my 244 properly adjusted without ever noticing the discrepancy!
:spank::eek:;)
 
Yeah i think I'm gonna have to just get a service manual afterall. I just got another 244 off ebay for parts or not working (fixing up old Tascams has become a sort of hobby of mine), and this one's gonna be challenge. I'm no stranger to overhauling the rubber, but I think some components have gone bad or theres a short on the Control PCB and Channel 2 Input AMPL PCB. Symptoms include the capstan motor always spinning (it should only spin when a cassette is inserted), the control mechanism seems to only want to be engaged in play mode, stop button has no effect on control motor. Channel 2 is weird - when I turn the 244 on Ch 2 gets no signal for about a minute, then it pops on, but its quiet and muffled. Can anyone think of what would cause a mixer channel to be like that? Bad cap, op amp...etc? I'd like to give this 244 a fighting chance.
 
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