EZ1084EQ NEW BATCH COMING - SEE MY MARCH 27 COMMENT ON PAGE 38

[dandeurloo]

wow, looks coo!

 

[Che_Guitarra]

I made two using dans case, with the eleven stepped option, and they both lined up perfectly. The extra steps make a big difference to my ears, so I'm glad I did it this way.

Does it require a different input pot to build up the 11-step version?  I've already ordered the parts from the BOM spreadsheet provided by Bluzzi, so if I need a different item it'd be good to know - just so I can order ASAP.

 

[Volume11]

I made two using dans case, with the eleven stepped option, and they both lined up perfectly. The extra steps make a big difference to my ears, so I'm glad I did it this way.

Does it require a different input pot to build up the 11-step version?  I've already ordered the parts from the BOM spreadsheet provided by Bluzzi, so if I need a different item it'd be good to know - just so I can order ASAP.

No, it's the same rotary switch. Check out the build docs. You can see how the switches are adjustable by using the two small pins provided with the switch.

 

[Che_Guitarra]

Oooh, getting excited - my (collective) cases from Dan arrived today.  Finished unit should look something like this:

Strapped for time over the next few days, and still a few bits and pieces to arrive, but i'll definitely make it an 11-step input if the parts needed for the job are in front of me   

 

[eparg]

First of two boards completed. Hard bypass and normal bypass are fully functioning (transformers sound great!) but the eq is not passing any signal. I triple checked all wiring and I re-flowed a few solder joints - still no luck. I used the TAW cap kit, AML kit, Dan's case, and exactly everything else listed on the BOM. All components were tested before stuffing and heatsinks were used when soldering the transistors. If anyone has a high res pdf of the 1084 schematic that would be greatly appreciated for trouble shooting.

Thanks!

- David

*EDIT*

Found a high res schematic. Back to troubleshooting.

**EDIT**

EQ is fully functioning now. Overlooked the low pass jumper pin (assumed I didn't need to jumper it because I was including it in the circuit d'oh!). Now it's time to buy a scope and calibrate, and then onto the second one. Thank you Jim and everyone involved for a fantastic project!

 

[eparg]

Oscilloscope arrived, spent a few hours scoping out the eqs. Sent a 1k rms sine wave @ .775v to the input of the eq and observed that there was no distortion of the wave form. I adjusted the trimmer to see what would happen and it didn't distort until the very end of the CW turns. Increasing the level to the input to the eq caused significant distortion and I adjusted from there, matching the distortion as best as possible. If anyone could chime in about what input voltage to use when calibrating that would be appreciated!

 

[Bonsaimaster]

Anyone know if and where I can purchase this PCB boards kit etc?

Thanks

 

[eparg]

Send an email to Jim at: ez1084eq(at)vibrolux.org

Not sure if he still has PCB's in stock

 

[Che_Guitarra]

Hi guys.  I'm needing the input of other's who've built these EQs.

I'm using the Five Fish 2448 power supply I assume most pair with this build.  I have an issue to troubleshoot - the unit's are emitting a lot of static noise, and I have a feeling the root of the issue is stemming from the PSU due to a few observed symptoms.

I need to know - with both unit's on, the most voltage I can get out of the PSU is 23.3V (requiring 24V).  Is this to be expected?  Have other's faced this issue with their power supplies?

 

[electrisizer]

i had an issue with FF 2448mk2 unit too. it was a hum around 120hz (i think to remember...) whats your noise?

BTW i was not able to solve the problem with this PSU and took another one that runs perfect till then.

 

[sharpeleven]

i had an issue with FF 2448mk2 unit too. it was a hum around 120hz (i think to remember...) whats your noise?

BTW i was not able to solve the problem with this PSU and took another one that runs perfect till then.

which one did you end up using (PSU)?

 

[Che_Guitarra]

FF sent me two kits (one more than I ordered), so I've build both.  On one of the kits a cap blew straight off the PSU PCB within 15 second of firing it up - the other one just can't muster a full +24V to the units.  I'm not sure if there is such a thing as 'dirty DC', but i'm getting a whole lot of static noise in the units, and the noise is exactly the same in both units.  I've emailed Bluzzi about possible troubleshoots but he must be a busy man at the moment.

 

[electrisizer]

i had an issue with FF 2448mk2 unit too. it was a hum around 120hz (i think to remember...) whats your noise?

BTW i was not able to solve the problem with this PSU and took another one that runs perfect till then.

which one did you end up using (PSU)?

i got a small +/-24v PSU from ebay. it was used in german broadcast studio before... a cheap solution too

 

[Che_Guitarra]

Hmmm...  do these cases need a direct ground?  I'm not getting any continuity from the enclosure to the 0 volt power pin... not sure I need to though?

 

[electrisizer]

Hmmm...  do these cases need a direct ground?  I'm not getting any continuity from the enclosure to the 0 volt power pin... not sure I need to though?

my grounding is: AC ground - PSU case - EQ case    -    NO 0v connected

but with fifefish PSU i tried nearly every ground sheme. nothing worked... in some grounding shemes a 50/60 HZ hum was produced. the 120 HZ hum/noise was always there.

so what kind of noise do you have?

 

[Che_Guitarra]

It's not a cycle or a hum - it's noise floor static, and lots of it.  This led me to believe it may be a grounding issue, but I may be completely wrong. In my previous post I was referring to my thoughts that the 1084 cases themselves may need a grounding point to 0V - I currently have no continuity.  I'm happy with the grounding in the FF PSU + PCB itself - continuity is checking out fine in the power supply.

As for the PSU, i'm concerned I can't get the full +24V to the units - it should be well within the PSU's range.  And the other day I popped three fuses in a row (in the +24V position) when I tried flicking through the 1084's bypass modes to pinpoint a source for the noise.  My only real observation was that in full bypass mode the noise was at it's least.  EQ engaged and the noise floor jumped real high.  Trafo on/EQ out and the noise got higher again.


But with those fuses going in quick succession i've decided to keep the unit's off in fear of damaging them - i'll just hang tight for wise advice.  I'm in over my head trying to troubleshoot this issue.

 

[Bluzzi]

I just got back from vacation with no internet so I am only now reading my over 100 emails. No worries we will get this sorted out.

I received your email so I will respond on those and one of us will post back here when problem is resolved.

Hang in there.

Cheers

Jim

 

[digistu]

FF sent me two kits (one more than I ordered), so I've build both.  On one of the kits a cap blew straight off the PSU PCB within 15 second of firing it up - the other one just can't muster a full +24V to the units.

I don't know whether this will be of any help for your second PSU, but I'm pretty sure the one pictured has one of the electrolytic caps in the wrong way round.  I've built a couple of these, and as I remember all the caps face the same way - in your picture, the one two above the blown cap is the opposite way from the rest.  Perhaps that was the problem with the blown cap too?

 

[Bluzzi]

A reversed electrolytic would blow in this case for sure.

FF sent me two kits (one more than I ordered), so I've build both.  On one of the kits a cap blew straight off the PSU PCB within 15 second of firing it up - the other one just can't muster a full +24V to the units.

I don't know whether this will be of any help for your second PSU, but I'm pretty sure the one pictured has one of the electrolytic caps in the wrong way round.  I've built a couple of these, and as I remember all the caps face the same way - in your picture, the one two above the blown cap is the opposite way from the rest.  Perhaps that was the problem with the blown cap too?

 

[Che_Guitarra]

Yep... an amateurs mistake  :-[  Can't believe I didn't pick that up.


Can I ask - are those with successfully working 1084s able to flick their bypass switch at will with the unit on?  I'm blowing fuses in quick fashion when I try to do so.