tascam m 3700 modification

hi,

ı have 2 tascam m 3700 32 ch 8 buss console and i want to modify them.What is your sugessions.But my idea is fix it to gather.(like large format)

A good mod might be changing the frequencies of the shelving filters. HF might be no problem, just changing R140 and/or C122 on the Input PCB. The LF section I don´t understand. It looks like a gyrator with a transistor instead of an OP. But it´s just a guess since I´m a jerk in audio electronic. Maybe someone else can help here. As a guess it should be changing C123 for getting another frequency.
Another thing is leaving phantom power on all the time. This gives the right polarization voltage to the coupling caps. This might be an easily achievable improvement (if you do use the Mikepres). But there is reason not to use them ;-). MAybe changing to another OP (U101) can help. IIRC it´s a 4558 which is not really considered to be the best in audio application. Check the metas about changing OPs or this link:
http://www.tangible-technology.com/audiobasics/upgrades/upgrade_2_opamps.htm
Maybe you have to work the PSU over since other OPs draw higher currents.
:sam:
Jens

I also have 2 M-3500 desks (3700 wothout the vca automation) interlinked to one desk

the 3700/3500 have a poor grounding bus (daisychained and not not beefy enough). this causes crosstalk into the auxbusses and other ugly stuff. so stargrounding the input modules close to the controlsection is a good idea.

if you dont need the inline channels, disable them by removing the busresistors. while you´re at it change the stereo bus (and the group busses (if you have the time)) resistors to metalfilm. this brings your bus noise to an acceptable level.

like Jens said, increasing hishelf frequency and decreasing loshelf is also a good mod.

changing the shown cap values will bring you there:

C122 6.8n for hishelf =12K instead ok 10KHz
C124 8.2n for loshelf =50Hz instead of 100Hz



the micpres are not bad...doesn´t make sense to mod

steff

Thanks, Steffen
Another good mod is to switch the auto off, if you don´t need it. There´s a lot of noise on the busses from this nasty piece of digitalelectronic.
Jens

thanks guys i wil try it.

ı have made some grounding already and i will check them again.

aris, please let us know how your results are.
cheers
Jens