Ladies and Gentlemen....well just gentlemen I suppose

    I started work on My EA Trem using RunOffGroove's PCB and Spec's, I had one of these years ago and decided to build another as I loved my other one so dearly...before it was stolen...  

     Anyway, I'm having a little difficulty, I'm not getting any effect when it is turned on, my rate light is working as its pulsing varies as I tun my rate pot, and my volume pot works.  My initial thought was that my depth pot had a solder bridge to ground or something to that effect but it has been double and triple..possibly pentuple checked and I cant see a problem there.  Any Recommendations? I'm guessing it's something incredibly stupid that I'm just too much of an ass to see...frustrating none the less

 Thanks in advance

Check the pinout of the JFET and all connections to and from it...

Quote from: gezCheck the pinout of the JFET and all connections to and from it...

Well I couldn't find any noticeable solderbridges near the jfet and I tried reversing it and swapping it out for another but to no avail.  However, no difference, no signal loss was made when I removed it from the socket, I'm not sure if that means anything...

Thanks

I had a similar problem building a Runoff EA trem...

I used a 2n7000 transistor at Q1 instead of the BS170. (Just watch out for the orientation)

Also, Anyone know where I can get a 250k lin pot in Australia?

Otherwise pedal sounds great

Quote from: Chris SAlso, Anyone know where I can get a 250k lin pot in Australia? Otherwise pedal sounds great

IF all else fails, you can use a 500K DUAL linear, connecting the corresponding lugs to each other. Or take a 500K and run a 270K and 220K resistor from the ends to the wiper, it should not distort the linearity much.

Thanks Paul!!! and so simple

Before you start loading the bullets, think this through.

Your LFO is working and your amp is working but there's no modulation, so it can only be a problem somewhere in the chain from the LFO's output (.47u cap) to the MOSFET's source connection (22u cap).

Check all your connections for open circuit/redo joints.

Edit: check the PCB traces for breaks/hairline connections between traces.

The bullets are loaded.

I'm not sure what that problem is, I've checked continuity between all points, made sure there were no connections between traces, replaced or resoldered everything between LFO out and MOSFET source.  I know a problem is there, I just can't find it.

I think I'll just scrap this board and try again since this is a fairly simple build, unless anyone has any tips.  Thanks for all the help and suggestions though gez

Could you just check that there's no DC voltage at the junction of the LFO's output cap (47u) and the 120k? It's possible that if the cap is leaky it's holding the gate more positive than source, which might account for the problem.

More likely to be Q2.  Wrong pinout/inappropriate trannie/poor joint/over-heating when soldering?

Try redoing the joints for the 22u electrolytic cap.

It's a long shot, but if it means saving a life...

Quote from: gezCould you just check that there's no DC voltage at the junction of the LFO's output cap (47u) and the 120k? It's possible that if the cap is leaky it's holding the gate more positive than source, which might account for the problem.

More likely to be Q2.  Wrong pinout/inappropriate trannie/poor joint/over-heating when soldering?

Try redoing the joints for the 22u electrolytic cap.

It's a long shot, but if it means saving a life...

Q2 was socketed so I don't think overheating is an issue and I've used several trannies.  If a leaky cap isn't the answer I'll have to flip a coin to see what get the gun first, the board or me :wink:

Go for the board (less messy!)  

Just checking, are you getting some voltage gain from the amp when the vol pot is at max?

just  gentleman i assume? I'm not female, but i think that is a rather ignorant statement.
I don't recall reading of a female board member specificially... but im sure if that is the attitude that would be recieved... there would be no reason why they would want to make aware of their sex.

My mom is a mechanic... no she's not a dyke, or ugly, or fat... all stereotypes that most people automatically think.  she has an understanding of mechanics that i will never even come close... i can't imagine how strong of a person she has to be to endure such blind ignorance.

In fact, she was the first certified female Seadoo (type of jetski) Tech in the U.S.A.

I didn't want this to turn into a flame/rant, but i think it is the resonsibility of everyone on a worldwide public forum to try and fight prejudice...

If we were all to assume all german members were nazi's...
... all people from the south are inbred...
... all people from california are rich...
we would be in a very bad social state.

When i moved back to England after living in America for 10 years i heard so many things that just blew my mind... they thought all americans had guns... that texas didn't have cars... and that we had no idea of what a hamster was...

with the great advacements of technology, which allow us to experience other's lifestyles whilst still remaining in our comfort zone in our safe little house, in our safe little neighborhood, in our safe little rut we call our mundane life... It is the reponsability of us all to help break down those walls and bring education instead of ignorance.

i think the best thing about this forum is the multi-cultural experience, there are so many people here with so many different perspectives...
i spoke with Ansil one time, and it just made me smile hearing an accent that i hadn't heard in a long time (he is from tenn). There is nothing wrong with having an accent, on the contrary, its nice to hear how other people react and respond to the same syllables and using the same human organs to make their own dialect of spoken language.

Its important to try and remember that with the broad spectrum of people in this forum, you can offend people with something that you may consider trivial.

This is nothing person to anyone, just a humble opinion by someone disatisfied with the attitude to, from, and within our different societies.

Lets try and step outside of our safezone... outside of our BOX and try and live things in someone else's shoes

...... que??

Quote from: R.G....... que??

myself, having been inclined to post a  :?:  a little while ago,
had to re-read the first line of the 1st posting to understand...

Quote from: SicWhen i moved back to England after living in America for 10 years i heard so many things that just blew my mind... they thought all americans had guns... that texas didn't have cars... and that we had no idea of what a hamster was...

Nah, Richard Gere disabused us of that notion…
:wink:

is your emiter of Q3 grounded?

just a thought,
hth

Hey, just finished an EA trem myself. If you have built the MOSFET version (you mention ROG so I assume this is the case), have you checked the biasing instructions for Q1 carefully? Stupidly, I carefully set the trimmer to give 4.5V on Q1's gate, and guess what? Low amplification, but no tremelo. Once I realised this (a few hours later), and re-set it for 4.5V on the drain, the circuit sprang into life.

Meanwhile, will all ladies who regularly post technical help on this forum please stand up? Hmmm... I thought so...

Regards to your Mum, Mr. Sic.

Quote from: Sicjust  gentleman i assume? I'm not female, but i think that is a rather ignorant statement.
I don't recall reading of a female board member specificially... but im sure if that is the attitude that would be recieved... there would be no reason why they would want to make aware of their sex.

My mom is a mechanic... no she's not a dyke, or ugly, or fat... all stereotypes that most people automatically think.  she has an understanding of mechanics that i will never even come close... i can't imagine how strong of a person she has to be to endure such blind ignorance.

In fact, she was the first certified female Seadoo (type of jetski) Tech in the U.S.A.

I didn't want this to turn into a flame/rant, but i think it is the resonsibility of everyone on a worldwide public forum to try and fight prejudice...

If we were all to assume all german members were nazi's...
... all people from the south are inbred...
... all people from california are rich...
we would be in a very bad social state.

When i moved back to England after living in America for 10 years i heard so many things that just blew my mind... they thought all americans had guns... that texas didn't have cars... and that we had no idea of what a hamster was...

with the great advacements of technology, which allow us to experience other's lifestyles whilst still remaining in our comfort zone in our safe little house, in our safe little neighborhood, in our safe little rut we call our mundane life... It is the reponsability of us all to help break down those walls and bring education instead of ignorance.

i think the best thing about this forum is the multi-cultural experience, there are so many people here with so many different perspectives...
i spoke with Ansil one time, and it just made me smile hearing an accent that i hadn't heard in a long time (he is from tenn). There is nothing wrong with having an accent, on the contrary, its nice to hear how other people react and respond to the same syllables and using the same human organs to make their own dialect of spoken language.

Its important to try and remember that with the broad spectrum of people in this forum, you can offend people with something that you may consider trivial.

This is nothing person to anyone, just a humble opinion by someone disatisfied with the attitude to, from, and within our different societies.

Lets try and step outside of our safezone... outside of our BOX and try and live things in someone else's shoes

On behalf of my gender I apologize for slandering us.  I have destroyed all work done since the Seneca Falls convention with my comment referring to a male dominated hobby, I'm sure our right to vote will soon be stripped.  Furthermore I would like to thank Sic for showing me the light, I will never post, say, or think anything involving gender, race, age, or disabilities.  Though it is now too late for me fix the damage I have done to my gender you can rest assure I will be boiling in my own excrement once I die.  The woman's league will have a signed, written apology in their main office tomorrow.  I am also accepting responsibility for all discrimination charges filed in the future, Iraqi prisoner abuse, and moldy cheese as I am sure I am responsible. Once again I aplogize for furthering these horrible stereotypes within the electronic hobbyist field, and would like to offer my sincere feeling of regret to Sic and his mother who have been deeply offended by my comments and communist sympathising ways.  The world would be a far greater place if we followed Sic's example, I will be building several churches in his honor shortly.



Don't derail a thread, if you got something to say to me PM me, keep threads on topic.  BTW I lived in Essex for nearly five years and Barcelona for ten, you shouldn't stereotype Europeans like that, I met maybe five people like that of which you speak, all of them were being facetious when speaking of such things. You hypocrite :wink:


Now getting back on topic, GEZ I owe you, swapped out the cap and the thing is golden.  Sounds great and I feel like a dumbass for not thinking of that sooner.  THANKS!

i guess you missed the point, but thank you for reading what i posted anyhow. i'd rather what i said to fall on deaf ears... than to not fall at all.

Thanks anyhow.

I Sterotype no one, and in doing so i stereotype everyone. I was Born in Ipswich Suffold England... so i do have first hand experience.

Quote from: gez

Quote from: SicWhen i moved back to England after living in America for 10 years i heard so many things that just blew my mind... they thought all americans had guns... that texas didn't have cars... and that we had no idea of what a hamster was...

Nah, Richard Gere disabused us of that notion…
:wink:

I thought he liked gerbils? is that the american word for hamster?