@blue2010 have you bypassed thetr control pod so it is just audio signal going straight into the sub's plate amp? rule out a volume problem in the plate amp first by sending audio signal directly to the plate amp (solder wires to audio ground and left + right input on pre amp panel in sub) if...

ok... just checking back in with the story thus far... i have been playing around with op-amplifiers making them operate in different ways and generally getting to know them. i had the idea that if i use a board i have (the original blown board that i fixed) i was going to try and cut pins 2 & 3...

@Abdiel  sorry i am fairly new to electronics and have not looked into filters yet... although i can see my self getting right into them after i have finished playing with attenuation and possibly doubling the tda7294 chips as to have the same config as the sub but with no filter... i have a...

i will have to experiment with op-amps at a later date... i did not do the comparison you did as i was having problems with op-amps so i bypassed all in one go... if you say they are the same then i will accept your testing but i will continue to try and change the attenuation... i will try this...

@A-Force i am pretty sure your problem will be with the op-amp as mine went quieter than the others and when i put a new one in it fixed it.   @ramachandra i have done the op-amp bypass on my board and have it running... but for some reason i think when i turn the volume up before it had more...

has anyone noticed that on this sub... the rear speakers are variable with the pod? and also the center speaker.... but only when the center and rear's are set at about half volume are they level with the front speakers... like the front speakers have got more attenuation on them? last time i...

OK... so i have double checked it and everything seems to be ok, missed one resistor (R627) but i corrected it :) this is the full schematic for the sub circuit which includes the power supply section and the pre-amp panel all in one. when my new meter turns up i will go over smd caps but they...

@ramachandra i have not found and as of yet either, the most i have found is for the pre-amp board, and parts of the pod for the signal coming into the pod and through the relevant circuitry and out of the pod to the sub (but no full schematic for the pod either). the schematics i have drawn are...

@A-Force i am new to this and have not done much experimenting with op-amps so it would be better for @ramachandra to answer your question :)       Here is the next schematic... it is of the power supply area, from the transformer's outputs to every point that supplies power to the sub and...

Here is the next one, i got carried away chasing the mute and standby pins of the tda7294 amps so i started at pin 8 on the pre-amp panel, pin 8 leads to most of the pre-amp board so i just did the pre-amp board now, will carry on with the sub schematic next.     EDIT : some things i cannot...

thanks, it is taking some time to do them, i did a little more on the sub schematic last night, got upto the U6 tda amp, done most of the pins on the U6, i have found how the system works the amps together... the U6 is the positive feed (non inverting on pin 3) which uses the wire on the back of...

@andro6600 sorry i did not comment on your mods, i have been looking through the forum now and then and keeping track but i have been using these pages for info while i have been frustrated with my own dooings lol.   great mods you have applied there, i like those heatsinks and those regs, in...

So i got back on this about a week ago, things are starting to go alot better now. i was being stupid and not using anti static equipment and not cleaning the tip, the problem was the tda amps i was soldering right/carefull enough. i focused on one and threw about 8 in one position (front left)...

yes i had the voltages wrong... i had a feeling they was wrong... i have another toroidal transformer which i must have remembered 11.4v from. yes mine is 240v... i would match the output voltages and the current capability for each output and it should fire up in a car.

@andro6600 i thought about the same thing... to put the sub into my car... they way i thought of doing it was either by using an inverter to step the voltage up from 12v to 240v and use the 240v in as usual into the sub (as long as the inverter has the correct current capability to handle the...

tda's turned up today... at first they had the listing for 50xtda7294 = £17 .. when i messaged them they said the listing was wrong and before i purchased they changed the listing to 10 X tda7294 = £13 ... so when they changed it i purchased anyway as it was still the best buy i could find on...

i will be back to this thread soon... i dont want to mess about with it anymore until the new tda amps turn up and i get some caps for the op-amp bypass (the third mod) i have had enough messing about with it lol i just want it back up and running again... i will report back in when the parts arrive

now a new problem has come to light... been reading alot about it... as i have moved the op-amps away and used wires to connect to the board... i think the op-amps are to far away from the caps and is causing oscillation (i think) all op-amps stay sort of at the same temp... around 40c... one...

ok... so the problem seems to have gone away... i took the amp off the back and thought about changing that op-amp... but first i used a d-sub connector i got from ebay and linked the correct pins and attached my rca's to that instead of soldering to the board... then i can just plug it in the...

yes this board does seem to have some problems... but i am not just here to mod... i am here to learn as well... so if i brake something i will fix it and make it work again (in the end). i think this time it is actually in the op-amp as i had this issue before and all i had changed is the...

Hmmm.... took it in the house last night and set it up... had it running for about 15 minutes and the rear left just producing audio and started doing the suck/pop thing again... annoying... i will just leave it for now... i am not messing about with op-amps again just yet... i have one brand...

i know it does not look great... but it works... it would not of turned out like that if i caught that tda amp a little sooner... oh well... on the next board it will have all new tda's and new op-amps... i know on the first board i will have had them in several times working it was just the...

ok... tda-amps turned up today... and well well... after 3 million op-amps later it turned out to be a tda that had snapped... the sub is working again and sounds mint... got all opa1612's in... elna silmic ii 50v 47uf & 22uf ... got the 0.22uf's on the underside... it int looking like a...

thanks for picture. my regs are only hot wen using the pod... you said yours are running hot when by passed aswrll? mine run cold when by passed. mine do get hot when running the pod but i am also running a 200ma fan on the pod aswell.

good to hear you got it sorted :) or running continously again at least. i realized when i had ur pic up... i was mainly looking at vregs... but then i noticed discoloured resistor and it rung bells lol. when u get those regs and try them please post what works well and what does not. not sure...