Reddish 500 EQ

[JMan]

Something is definitely wrong with this picture.

-You have signal on the primary side of the input transformer.
-We have checked the secondary side of the transformer and all the connections immediately thereafter, all of which show no faults in the path.

If the above statements are true, we should have signal on R0.

The only possible other explanation I can think of is that somewhere along the path you have a solder bridge or something similar that is shorting the audio path to ground.

Go back to post #377 and follow the audio path again, but this time instead of measuring AC voltage between each of those points in the circuit and Aud GND, go through it once with your meter set to continuity mode. If you don't get the continuity beep anywhere, go through it again measuring ohms. Please report back with your findings.

 

[inf0]

I will be having Polystyrene nightmares for the next decade.

It ended up being very easy to sort them out but the planning took a bit of time !
Would love to thank @JMan , @ruffrecords , @Kevin and everyone who contributed to this project.

We are all very lucky to be part of this beautiful community!

Onto the next

 

[JMan]

Beautiful work!

 

[capacitorless]

Polystyrenes are the route I'm taking as well, and it is super awesome to see how it's done! Looks great!

 

[inf0]

Polystyrenes are the route I'm taking as well, and it is super awesome to see how it's done! Looks great!

From my experience, starting from the capacitors in the middle and working outwards seemed to work out pretty well ! Towards the end , you would need to check how they can fit around the grayhill switches but it's pretty simple.

Also , I've used the sleeve off 24awg PTFE wires on some of the leads to isolate them and it worked wonders! Ofc you could do the same with shrink tubing but I was too afraid getting heat anywhere close to them !

 

[capacitorless]

Great information and thank you! I'm planning on using an alligator clip to heatsink each lead as it is soldered. I just need to save up for a bunch of styrenes, haha!

 

[JMan]

If you're using polystyrene caps, here's a hot tip: you can replace certain pairs of capacitors with single caps of an equivalent value. Due to the fact that the WIMAs that this project was designed around come in a fairly limited number of values, certain overall values had to be achieved by using two caps in either series or parallel. However, since polystyrenes come in many more values and have a larger form factor, you may find it easier to do it with a single cap.

For example, a 22nF and a 100nF in series can be replaced by a single 18nF cap, which although not available from WIMA, is available as NOS polystyrene.

You could look in the schematic and see if there are other pairs that could be similarly substituted. Just be sure that you are being mindful of whether the pair is in series or parallel so that you don't get bad calculations.

 

[capacitorless]

It's late in the game, but I'll do that and publish the results to this thread.

 

[JMan]

It's completely up to you. That's just something that builders can consider, and it might help make more economical use of the space when using large polystyrene caps.

 

[electrisizer]

ive finished the EQs too they do have big polysterene caps too. i ordered some via reichelt and had some nos lying around. the nos caps do have very big solder leads so i havent isolated them. once soldered in they are difficult to move...

the only problem i have, the frontpanels are bit too broard for my 500 rack. i dont get 4 EQs next to each other. i will try to file down the panels.

havent used the EQs for mixing yet. ill report back.

 

[inf0]

My god , this thing sounds expensive.. Sounds amazing
If there is a re-run of the boards I'm definitely buying a few more.

@JMan Is it an easy task to change the low band to a different frequency? I would love to build 2 of them with the low band around 60hz just to have a different flavor.

 

[JMan]

My god , this thing sounds expensive.. Sounds amazing
If there is a re-run of the boards I'm definitely buying a few more.

@JMan Is it an easy task to change the low band to a different frequency? I would love to build 2 of them with the low band around 60hz just to have a different flavor.

I'm glad you like it! Credit to Ian for the brilliant (pun intended) circuit.

You'd have to do some math to work out whether 60Hz is possible. You'd have to recalculate the five RC filters on the cut side, and the R and L values for the boost. If you couldn't figure a way to do it with the 7H from the UTM1543, it does have a 10H tap as well that you could fiddle with to see if you can make it work - that would require cutting a trace and running a wire, not the hardest thing for a DIYer though. Maybe @ruffrecords could chime in here, since he has a particular talent for these sorts of things.

 

[Forcemusicgroup]

Something is definitely wrong with this picture.

-You have signal on the primary side of the input transformer.
-We have checked the secondary side of the transformer and all the connections immediately thereafter, all of which show no faults in the path.

If the above statements are true, we should have signal on R0.

The only possible other explanation I can think of is that somewhere along the path you have a solder bridge or something similar that is shorting the audio path to ground.

Go back to post #377 and follow the audio path again, but this time instead of measuring AC voltage between each of those points in the circuit and Aud GND, go through it once with your meter set to continuity mode. If you don't get the continuity beep anywhere, go through it again measuring ohms. Please report back with your findings.

beeps at r29 ,r25,r27,28
-Both sides of R0 - left leg = 1.68koms, right = 0.75kohms
-the bottom leg of R11 -10.4k
-the top leg of R25 - 4.52k
-Both sides of R27 - left leg = 3.9ohms, right = 3.1ohms
-Both sides of R28 - left leg = 1.68koms, right = 0.75kohms
-the right leg of R29 - 8.2ohms