Akai 4000DS MKII Recording Level

[TinCanAlley]

Hi all....

I'm hoping this is a simple adjustment, but something tells me I'm gonna need a few items I don't have.

When I want to record on my deck, I set the level based on monitoring the source. Once I get the needles peaking where I want them, I start recording. Now if I switch to monitoring the tape as it's recording, the level jumps by more than 3db and the meters are pretty much pegged in the red. So I'm guessing there must be separate adjustments for the source level and the actual record level, right? If that's the case, do I need a tone generator and such or can I play a 1kHz tone from a test CD and measure the output with a DMM and adjust the pots (probably not as simple as that)?

Thanks in advance!

Oh, I recorded Dire Straits' Brothers in Arms and once I readjusted the recording level, the results were a very good sounding copy, so other than recording level issue, the deck seems to be working perfectly. :thmbsp:

[Strawman]

Welcome Tincan,
Have you started with the easy stuff? Clean & demag the tape path, flush out the switches and pots with Dexoit?

[TinCanAlley]

Welcome Tincan,
Have you started with the easy stuff? Clean & demag the tape path, flush out the switches and pots with Dexoit?

She's got new belts, been deoxited, heads cleaned and demaged (with original Akai demagnatizer) across the entire tape path. She plays back pre-recorded tapes perfectly and as long as I set the recording level by monitoring the recording output, she records and plays back perfectly.

She seems to like Quantegy 406, so I only feed that to her and I clean her tape path and heads every 10hrs or so of play/rec. I demag the heads once a month (more often if I'm doing more playback/recording).

Thanks!

[Strawman]

It certainly sounds like you're taking very good care of her. Have you checked out the manual download from Hifi engine?
I want to try some of that Quantegy on my decks, but always seem to forget when I'm watching them.
The best I've fed mine so far are Maxell UD-35.
I'm wondering if it might be a bias adjustment. Keep checking back, there are some very knowledgable folks around here.

[Stone Free]

Hi friend,

Try to adjust your deck following the directions at the 4000DS/DSMKII service manual:

http://i81.photobucket.com/albums/j212/stone_free/4000DS.jpg

For a 1000Hz frequency source, try a software like NCH Tone Generator straight from your PC soundboard output. The hardest part is to find a 250 Hz test tape, but I think that's easier in US than in Brazil, where I live.:D

Good luck.

Regards,

Gustavo

[TinCanAlley]

It certainly sounds like you're taking very good care of her. Have you checked out the manual download from Hifi engine?
I want to try some of that Quantegy on my decks, but always seem to forget when I'm watching them.
The best I've fed mine so far are Maxell UD-35.
I'm wondering if it might be a bias adjustment. Keep checking back, there are some very knowledgable folks around here.

I just downloaded the manual. It was in 4 parts.

I got a box of 10 pancake reels off ebay of the 406 for only 49.00! :banana: There was enough to make 20 7" reels. That much tape from online vendors would have cost more than 400.00!

I was going to try the 456 or GP9, but I doubt the bias on my deck is setup for those. Too expensive to try since the 406 works like a charm.

[TinCanAlley]

Hi friend,

Try to adjust your deck following the directions at the 4000DS/DSMKII service manual:


For a 1000Hz frequency source, try a software like NCH Tone Generator straight from your PC soundboard output. The hardest part is to find a 250 Hz test tape, but I think that's easier in US than in Brazil, where I live.:D

Good luck.

Regards,

Gustavo

Thanks for the image from the SM. Looks easy enough, but like you wrote, the 250Hz tape might be an issue. I guess I could create a tape on my brother's deck, then play it back on a couple of different decks to verify it recorded properly.

I have a CD with a 1kHz tone on it. It's at -20db. Do you think that would be okay to use, or is the possibility the CD players outputs might not send out a true 1kHz signal?

[Strawman]

Yes, thanks for the scan & welcome aboard Stonefree. :thmbsp:
Nice snag on the 406 there Tincan. Good luck on solving that issue!

[Stone Free]

I have a CD with a 1kHz tone on it. It's at -20db. Do you think that would be okay to use, or is the possibility the CD players outputs might not send out a true 1kHz signal?

:nono:I don't think so. You'll need a 1kHz at a rigorous 0dB signal. In my experience, tone generator softwares are by far, more precise than anything else. And they're very easy to use, also.

I guess I could create a tape on my brother's deck, then play it back on a couple of different decks to verify it recorded properly

Yep, once you have find an adequate deck, make yourself a test tape, recording a 250Hz/0dB sine wave signal with the same software.

Yes, thanks for the scan & welcome aboard Stonefree.

Not for this, Strawman. My pleasure:thmbsp: I already made my debut at the Introductions Forum!!!:yes:

[Strawman]

Not for this, Strawman. My pleasure:thmbsp: I already made my debut at the Introductions Forum!!!:yes:[/QUOTE]

I'll still say that I think you will be a valuable asset to this forum Gustavo.
I'll admit that I don't get to the Into area as often as I might want to, so I just wanted to thank you for your participation here. :thmbsp:
Steve

[Stone Free]

Thanxs Mr. Moderator. My honour in participating and helping people in order to keep their vintage machines (mainly those AKAIs) working properly as well as trying to bring 'em back to life. That's my goal.

Cheers:beerchug:

Gustavo

[TinCanAlley]

:nono:I don't think so. You'll need a 1kHz at a rigorous 0dB signal. In my experience, tone generator softwares are by far, more precise than anything else. And they're very easy to use, also.



Yep, once you have find an adequate deck, make yourself a test tape, recording a 250Hz/0dB sine wave signal with the same software.



Not for this, Strawman. My pleasure:thmbsp: I already made my debut at the Introductions Forum!!!:yes:

Okay, I got the tone generator and my meter showes that at 0db from the sound card, the output level is only 12mv. I used the software to create a 1000kHz 0db wave file and then used a program to create an audio CD from the file. The result is an audio CD with a pure 1000kHz 0db tone (frequency meter verifies). Measureing the output level of the CD player gives me 50mv. The Akai has a max input level of 70mv, so this is going to work.

I used the same program to create a 250Hz 0db file so my brother can create a tape on his Pioneer deck. He will then play it back on two different decks to make sure it's recorded at 0db and a frequency meter to make sure it's still 250Hz. I will use this tape to adjust my playback level before I attempt the record levels.

Wish me luck!

[Stone Free]

Well, TinCan...

Good LUCK!:thmbsp::thmbsp::thmbsp:

Regards.

Gustavo

[Strawman]

Best wishes, please keep us informed of the outcome. :thmbsp:

[TinCanAlley]

Success! :banana:

After realizing that in the service manual when it states 4db, it actually mean -4db, I was able to set the playback level with a 250Hz 0db tape and then set the record and souce levels with a 1000kHz 0db tone. Now when I record at 0db, the source and tape monitoring do not change going back and forth between them.

I tested the deck with several pre-recorded tapes and the output level was perfect. I also recorded Dire Straits' Brothers in Arms and it played back better than I could have hoped for on this vintage deck (Quantegy 406 tape was used for this recording). The highs, dynamic range and S/N were perfect. I'm a very happy camper now.

Thank everyone for their help and support! It's greatly appreciated! :thmbsp: