Messages

[TL062cp]

Hi, I've got 3 of each type of MN3007 and MN3101 that are all from different but trusted sources. the mn3101's i have tested in a delay and work well. the MN3007's are known to work from a past chorus build. I cannot for the life of me work out whats going on, could someone please cast an eye over my board and check the voltages I'm getting? thanks in advance.







Voltages are as follows:

TL062cp
1=8.58v
2=0.3mv
3=8.57v
4=0.4mv
5=0.3mv
6=6.25v
7=8.58v
8=9.25v

JRC4558
1=4.45v
2=4.46v
3=4.45v
5=4.46v
6=4.45v
7=4.45v
8=9.25v

MN3101:
1=9.15
2=4.66
3=0.4mv
4=4.71v
5=315mv
6=8.15v
7=2.5v
8=0.619

MN3007
1=9.16v
2=4.72
3=3.76
4=0.62v
5=0.4mv
6=4.68v
7=3.74v
8=3.74v

Hopefully this is enough for a kind hearted individual to help me fix this bugger!!

This is great news that another has been solved. I do believe that the issue should be raised in the build docs though.

It's not very clear in the document but it is there that it should be left out.

It indeed needs to be removed, this thing sounds freaking awesome!

Just need to fine tune an option i added and it's finished.

Thanks a bunch Y'all!

Woohoo!! Congrats man

oh and is there any chance the build docs can make it clear r13 and R14 should be socketed 100%? it seems to be quite important..

Why it has been such an issue i'm not so sure, I question if it's the chip brand but i'd have to see some data to support it.

Some reading of the compander cookbook should make it clearer, I believe it has the biasing equation, it's possible with a different production line the same equation no longer applies.

sounds like dry read!! seriously though, thanks for the help. very much appreciated.

oh and is there any chance the build docs can make it clear r13 and R14 should be socketed 100%? it seems to be quite important..

Cool, audio probed the circuit (which enabled me to bias the mn3005's without a signal getting to them) it was the signal between the com pander and the MN3005 that was weak. I adjusted R13 and 14 to 18k each and the delays rang through clean and clear.......

thank you for your help, really glad this got sorted because its such a great sounding delay.

and to prove my build is complete here are the guts etc:

ok, here are the voltages running from a 9v supply:

353 chipe

1=4.58
2=4.58
3=4.55
4=0
5=4.58
6=4.58
7=4.58
8=9v

062 chip

1=floating
2=4-5v float
3=3-5v float
4=0
5=4.58
6=4.58
7=4.58
8=9v

sa571n

1=0.9
2=1.8
3=1.8
4=0.3
5=1.8
6=1.8
7=2.9
8=1.8
9=1.8
10=4.8
11=4.8
12=1.8
13=9.16
14=1.8
15=1.8
16=0.8

MN3005
1=8.98
2=4.5
3=4.6
4=4.6
5=0
6=4.5
7=4.4
8=0.6

MN3101
1=9
2=4.5
3= 0
4=4.5
5=2.9-3.9 float
6=4.9-5.5 float
7=4.1-4.5 float
8=0.6v

Are you sure about your pin 13, that should be your supply.

Full voltages from both of you would make the whole thing clearer.

My error, I counted down on lhs rather than up. I'll correct tomorrow and give a full voltage readout for all chips.

I don't know what happened, but I swapped 10k's for the 39k's I had in R13 & R14, I moved the bias trims CW in small increments until the repeats were clean.  I still got some tweaking to do, but it's useable now

You're looking to bias the compander output to 1/2 supply, so what's the voltage on Pin 7 & 13 of the 570/571.

With the 10k's in 13 and 14 as per the docs, I get 2.94v on pin 7 and 1.89v on pin 13. Worth increasing the values of 13 and 14?

Hi, I hate having to ask for help but....... I'm stuck.
I've spent the day building an aquaboy dx using:

2x tested mn3005 (tested in a dod fx90)
1x tested sa570 compander
1x mn3101 also tested

I've tried everything I can think of, including:

reflowed all joints
Checked all resistors
Checked all caps
Checked polarity/ orientations

The good:

Bypass is clear
Dry signal is good
I get clock noise when I adjust the clock trimmer (9v on pin 1)
The vactrol and lfo portion is working- rate and depth knobs work
The mix knob works
The depth knob adjusts the freq of the clock noise heard

The bad:

No matter what I do there is no delay at all.


I had d3 installed initially- cut out now- mn3101 retested and still works
Running at 9v and see 9v at the pin 1 of each mn3005.

What else can I do? Any suggestions?

i am going to go back to this one after ive done a bit of research, there are so many options. but it strikes me that you could get a pedal that could emulate the  full tube compliment.

whether or not this is any use to the effect pedal world is debatable but imagine a pedal with either opto-fet or a well designed diode clipping section to represent the preamp and fets to represent the power tubes.

a true amp in a box?

i haven't tried any of the runoffgroove AIABs, or any clones of commercail types, but i did my own exploration into this AIAB idea back in 05. 'decade'
it has a JFET feeding a Ge trans, a dumble-inspired tone stack and a 3rd FET tage. the trimmers on the FETs allowed tuning to emulate preamp and power amp distortion, the Ge gave a round tubey flavor ( and player dynamics) that FETs alone couldn't match IMO.

Looks really nice,
If the dynamics are so difficult to emulate, why don't more pedals utilise the opto-fet like in the bixonic expandora? I've only seen this in this pedal and it seems a really neat way to ensure picking strength etc are taking into account to give a good distortion characteristic.

I see ive opened a can of worms, I literally had no idea it was that hard to convert. I was just reading the Fetzer page on runoff groove now. Blimey!!!

All i was thinking is well this is the preamps, what about the tonestack, power section etc etc. I need to do more reading on this stuff, its very interesting and clearly if nailed right can work. Why hasnt the azabache been made into a production pedal i wonder?

ref the paisley, yeah I'm going to buy one of those i think. thanks for the link.

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1. Not bad form, just a post in the wrong place. I don't think it's necessary to move, because the original topic has been derailed, so if you'd like to repost in the Requests area, that's fine.

2. Again, just because you're being pointed elsewhere doesn't mean you should question your ideas, but rather join the conversation.

3. I agree, you don't need an amp to find the schematic. However, in most cases, turning an amp into a pedal is a big and complicated task.

I think you may have gotten an inaccurate reception here, so our apologies on that one. Let's start over! Welcome, you're very welcome to join, ask questions, and participate on all of the forums here. We like that, and we have no issues with you. I'd encourage you to read a lot more, ask questions, and look at the suggestions people offer as chances to join in on the conversations.

It's a bit of an aside, but perhaps the best person to take the Trainwreck amp schematics and turn them into pedals is you. It's certainly in the realm of possibility, although you may not realize it yet.

Jacob

Hi Jacob, thanks for the welcome- I've actually been around lurking for quite a while and post under the same name on the BYOC forum- I know bits and bobs about circuits and really should find the time to learn the fundamentals of circuit design from the ground up, its something ive been meaning to do having built hundreds of pedals now.

-  you are probably right i should just do this myself, it'll be a good learning experience. That being said, id actually quite like to build the amp- hmmm......

Dude, calm down ...

I am calm. Life's too short to get excited by the internet. Im a military guy and one of my failings is abruptness in conversation be it text or speech. That being said, I was asking a genuine question, as in is it bad form to make requests? I didn't realise there was a requests section, happy for this thread to be moved by a mod though if it'll help?

The reason i asked was because this is the second time in about a month i have done so and in both cases i was pointed elsewhere, so i was getting the impression that either a) my ideas are shite or b) its not the done thing to suggest builds.

And i do understand that Brian wont have access to a real Trainwreck amp but the schematics are available on the web so i assumed he may be able to work his magic as i don't have a clue how to convert an amp into pedal form.