OT: tech12 bassdriver pcb
- Thread starter 12afael
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jensenmann
Well-known member
:thumb: thanks, mate
:guinness:
:guinness:
clintrubber
Well-known member
Thanks for sharing.
Having never toyed around with this box I'm wondering where the 'overdrive' comes from, I see only filtering but no diodes or something.
Regards,
Peter
Having never toyed around with this box I'm wondering where the 'overdrive' comes from, I see only filtering but no diodes or something.
Regards,
Peter
clintrubber
Well-known member
[quote author="Nikolay"]The sansamp technology is based over operational amplifier clipping. Tech21 used Cmos opamp which have smooth clipping and sound near tube clipping. Lisen GT2 for example.[/quote]
Whoa, surprised a bit by this. Thanks for pointing out.
Whoa, surprised a bit by this. Thanks for pointing out.
new revision.. drive and treble were backwards too. icon_redface just in case you want to wire the pots directly on the board.
we have another issue. when the level and blend are at max the unit don´t pass audio. it´s like a bad biased device, maybe there is a resistor missing on the triangula ear schematic.
Rafael
we have another issue. when the level and blend are at max the unit don´t pass audio. it´s like a bad biased device, maybe there is a resistor missing on the triangula ear schematic.
Rafael
it use a spdt the common is wired to SW3 and the extremes to SW1 and SW2. check the original triangular ear schematic for more details. parts numbers and values are the same on my board.
http://home.planetahost.ru/~firewood/teb21.pdf
yes it use a 9V battery .
http://home.planetahost.ru/~firewood/teb21.pdf
yes it use a 9V battery .
ok i jumped the gun and etched the revision 1 board. Do you mean that by the drive and treble being backwards I just need to wire them up reverse. I plan on wiring of board so this will not be a problem, i just want to clear this up. I am hoping to have this done in time for a weekend gig. Also will wiring in a led to indicate when the unit is on affect battery life much?
yes the drive, treble and precense were backward, the precense can not be mount on the board so just wire it up reverse.
the unity draw aprox 22mA a led can draw 20ma more ( it depend of how many light you want. )
40mA is still healthy. some delays draw 150mA
the unity draw aprox 22mA a led can draw 20ma more ( it depend of how many light you want. )
40mA is still healthy. some delays draw 150mA
:grin: I got this completed except for an enclosure. Sounds good to me, makes my rogue bass sound much better, i mean much better. I am not getting much response out of the treble, but i will have to track that down tommorrow. I didn't have any problems with it not passing audio as described earlier in the topic. This is a great preamp, and cheap to build for anyone looking to build this.
thanx for the report, what IC did you use?
so with the blend at clean and the level at max there is not problem?
I will begin it next week.
with some thin jacks you can mount it on a hammond 1590BB a friend of mine did it.
so with the blend at clean and the level at max there is not problem?
I will begin it next week.
with some thin jacks you can mount it on a hammond 1590BB a friend of mine did it.
I did run into the problem with the blend last night. I used ti tl072s and 74s. The sound it great. I do plan on testing different opamps. I will tell you this if you do not get the grounding right it will sound horrible. All is well with the unit except for the blend level problem.
that problem is turn me crazy... I have a similar issue on the amek2500 eq project. I`ve reading the TI book "op amp for everyone", I suspect that at some point there is not current on the inputs from + to - on the op amp. it is a small issue on the bassdriver and a small R on one pot fix the problem but I want to know why.
