Check Nielsk's group buy thread in the Black Market, which is where information on that group buy is being shared.
Reddish 500 EQ
- Thread starter JMan
- Start date
Help Support GroupDIY Audio Forum:
First and most importantly -- did you remember to contact Igor/UTM and request that they be custom wound for 600:600?
If so, do not worry, it will be quite easy to wire up correctly. However, I want to wait until we know the answer to the first question before describing the solution, because if you bought the stock part by mistake and the wiring is any different (I'm wondering if the custom-wound one has the black and blue leads or not), I don't want to cause any confusion for other builders reading this.
EDIT: Just adding, the reason that the lead colors are different if you use the UTM is that I designed the project around a Cinemag transformer and the UTM was an option that was thought of by Herbert when he was helping me proof the boards. It's normal for different transformers from different manufacturers to have different lead colors -- as far as I'm aware, there is no standard for this (nor any reason to have one).
janczmok
Well-known member
I originally asked Igor/UTM to have custom-wounds, but it seems it somehow got lost in context; you can PM me directly and provide infos, however mine (which is MAYBE the wrong ones, looks like this):
Also i will take measurements to see how they compare to the datasheet
Edit: Odd values (Multimeter in Ohm Mode, maybe i am doing something wrong)
red-yel = 8.4ohms
or / bl = 17 ohm
blu / grn 17 ohm
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Hey janczmok, I PM'd you about the wiring. If it turns out that this is the 600:600 transformer, I'll add that info to the thread as well.
Regarding the measurements, unfortunately I think you've measured DC resistance, which won't tell us much about the impedance ratio (which I believe is an AC-related thing). Maybe someone with better knowledge about transformers can suggest a way of working that out.
@HerbertR @nielsk did the 600:600 version of the UTM output transformer that you received have six leads or four? I'm suspicious because there would be no point in having the dual secondary windings, but I did not use these in my build so I don't know what should be expected.
Regarding the measurements, unfortunately I think you've measured DC resistance, which won't tell us much about the impedance ratio (which I believe is an AC-related thing). Maybe someone with better knowledge about transformers can suggest a way of working that out.
@HerbertR @nielsk did the 600:600 version of the UTM output transformer that you received have six leads or four? I'm suspicious because there would be no point in having the dual secondary windings, but I did not use these in my build so I don't know what should be expected.
Hi, the Custom Output UTM TX has two secondary windings. It can therefore also deliver 150 Ohm as secondary when connected in parallel.
simple connection for 600 Ohm operation:
- Green TX cable goes to the "Yel" soldering point on the PCP
- Yellow TX cable goes to the "Red" soldering point on the circuit board
- Orange TX cable goes to the "Or" soldering point on the circuit board
- Red TX cable goes to the "Brn" soldering point on the circuit board
- Blue and red TX cables must be connected/soldered together/shorted for 600 Ohm operation
I think it should also work Primary and Secondary reversed.....Thats it
simple connection for 600 Ohm operation:
- Green TX cable goes to the "Yel" soldering point on the PCP
- Yellow TX cable goes to the "Red" soldering point on the circuit board
- Orange TX cable goes to the "Or" soldering point on the circuit board
- Red TX cable goes to the "Brn" soldering point on the circuit board
- Blue and red TX cables must be connected/soldered together/shorted for 600 Ohm operation
I think it should also work Primary and Secondary reversed.....Thats it
Attachments
Thanks Herbert!
That information matches what I sent to janczmok via PM as well. So, anyone using the UTM output transformer can use that wiring scheme to correctly hook it up. EDIT: one minor but important error in Herbert's post above that I missed initially - Blue and Black should be connected, not Blue and Red.
Please note that this information is for the UTM transformer only! If using the original Cinemag transformer, the lead colors correspond directly to the silkscreen on the PCB. If using a different transformer, you must compare your data sheet to the Cinemag and place the leads accordingly.
That information matches what I sent to janczmok via PM as well. So, anyone using the UTM output transformer can use that wiring scheme to correctly hook it up. EDIT: one minor but important error in Herbert's post above that I missed initially - Blue and Black should be connected, not Blue and Red.
Please note that this information is for the UTM transformer only! If using the original Cinemag transformer, the lead colors correspond directly to the silkscreen on the PCB. If using a different transformer, you must compare your data sheet to the Cinemag and place the leads accordingly.
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slipperyflax
Well-known member
I may add that in my contact with Igor of UTM he said that they've had enough interest in the custom 3523LP 600:600 that they would add it to the webshop. Hasn't happened yet but he said he'd keep me posted 
NOON
Well-known member
PCB and metalwork sets arrived in Australia today! They look great quality, nice work on the layout. Just need to keep gathering all the other parts required as I can afford them.
i received the replacement brackets they exactly fit the pcb, They added the powder coating since they thought it was ordered like the first initial order just with wrong holes. I asked to do without powder coating and they probably added it somehow. the pcb didn't have the usual pin1 in the corner connection. but to get a good metal contact easily scratch off the hole at the transformer in the top right, then there will be good chassis connection.
there is also no reason to do them again without powder coating, since the shielding still can easily achieved.
the advantage of powder coating is we don't have bare metal and the metal will be more safe against external damage. so we will more years fun with these modules. compared to bare aluminium we also have no scratches or anything left after the cnc process and it look way better then without.
i will send them out in the beginning of next week. if you don't get a tracking number during the next week from me, then keep your brackets as shipped since these envelopes have a tracking number but that one is not traceable. and yes if i send out the tracking number and it says not traceable, it's on the way and from my experience they will arrive anyways, just give it some time
there is also no reason to do them again without powder coating, since the shielding still can easily achieved.
the advantage of powder coating is we don't have bare metal and the metal will be more safe against external damage. so we will more years fun with these modules. compared to bare aluminium we also have no scratches or anything left after the cnc process and it look way better then without.
i will send them out in the beginning of next week. if you don't get a tracking number during the next week from me, then keep your brackets as shipped since these envelopes have a tracking number but that one is not traceable. and yes if i send out the tracking number and it says not traceable, it's on the way and from my experience they will arrive anyways, just give it some time
I decided to design my L-brackets and front panels for this, primarily because I have never done any of that for 500 series and want a new challenge. While working on the CAD drawings today, pulling a bunch of measurements with my calipers, and looking at data sheets, I came across something that I wanted to point out regarding the Grayhills and push button switch centerline alignment on the front panel.
Per the 500 series standard, the centerline of the PCB to center of the front panel is 11.1252mm (.438 inches), which @JMan has right on the money with the push button switch location. If you subtract half the thickness of the main PCB from that dimension you’re left with 10.3252mm, but the Grayhill center of shaft to bottom of the mounting pad(s) is 9.35mm, so if you mount them flush to the PCB then your push button switches will be shifted to the right .9752mm when you install the front panel. I didn’t notice before, but you can see it if you look at the photos in the first post. It’s not end of the world, but it could cause the buttons to rub, depending on the size of the opening in the front panel. What I’m going to do is include a few slots in my L-bracket design that allow me to bolt it all up and tack a few pins on the Grayhills with them where they need to be, then take it apart to do the final soldering on them, similar to what I’ve had to do with some steps of other kits I’ve put together. What you all can do if you want to correct this is find something that’s close enough to .97mm thick (I think some small flat washers are about .9mm) and place a couple of them under the edge of the Grayhills while you tack a few pins, or Dremel a few openings in your L-bracket to access the pins and do what I’ll be doing. This also keeps the main PCB perfectly perpendicular to the front panel when installed in the rack and maintains a straight entry into the 15-pin connector. I’ll try to finish a drawing in the next day or two that’ll give you a visual and post it here, if that makes it easier to follow.
Per the 500 series standard, the centerline of the PCB to center of the front panel is 11.1252mm (.438 inches), which @JMan has right on the money with the push button switch location. If you subtract half the thickness of the main PCB from that dimension you’re left with 10.3252mm, but the Grayhill center of shaft to bottom of the mounting pad(s) is 9.35mm, so if you mount them flush to the PCB then your push button switches will be shifted to the right .9752mm when you install the front panel. I didn’t notice before, but you can see it if you look at the photos in the first post. It’s not end of the world, but it could cause the buttons to rub, depending on the size of the opening in the front panel. What I’m going to do is include a few slots in my L-bracket design that allow me to bolt it all up and tack a few pins on the Grayhills with them where they need to be, then take it apart to do the final soldering on them, similar to what I’ve had to do with some steps of other kits I’ve put together. What you all can do if you want to correct this is find something that’s close enough to .97mm thick (I think some small flat washers are about .9mm) and place a couple of them under the edge of the Grayhills while you tack a few pins, or Dremel a few openings in your L-bracket to access the pins and do what I’ll be doing. This also keeps the main PCB perfectly perpendicular to the front panel when installed in the rack and maintains a straight entry into the 15-pin connector. I’ll try to finish a drawing in the next day or two that’ll give you a visual and post it here, if that makes it easier to follow.
I continue to admire your precision! Would love to see a drawing or some photos of the solution you described once you have them.
FWIW, this was a concern of mine as well initially, but I've built a couple units now and as long as you're mindful as you pull it all together, you can get everything to sit as accurately as any other piece of DIY or commercial gear I've used. However, the perfectionist in me is really excited to see what you do!
FWIW, this was a concern of mine as well initially, but I've built a couple units now and as long as you're mindful as you pull it all together, you can get everything to sit as accurately as any other piece of DIY or commercial gear I've used. However, the perfectionist in me is really excited to see what you do!
Thanks bud! It'll be quite a while before any photos of mine surface haha. I wasn't expecting to start on anything with these until I finish my last two in-progress rack projects, but I have more time than extra money right now and decided to see what I already have in stock for these so I could get the time consuming BOM and parts sourcing out of the way, then started messing with the drawings. Gonna stuff one pair with polystyrenes and Carnhills/Cinemag, the other pair with WIMA FKP or MKP (FKP until the size is an issue, then switch to MKP) and UTM, and maybe do something like red frequency select knob for the ones with WIMA and grey for the ones with polystyrenes, to differentiate the two in the rack. I'm already daydreaming about trying an Orange 86 > Reddish 500 > D-LA2A chain, using all my latest builds.
Attached is a drawing of what I was mentioning about leaving a .9-ish mm gap between the Grayhills and main PCB for an aligned vertical centerline with the push buttons.
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I also wanted to mention that you can spread R5 and R10 enough to use a Bourns 3266-size trimmer for R0 if you’d like. I had one in the wrong value that I used as a gauge. I’m going to use a 5k pre-trimmed to 2.4k to start.
slipperyflax
Well-known member
Here's the linkI may add that in my contact with Igor of UTM he said that they've had enough interest in the custom 3523LP 600:600 that they would add it to the webshop. Hasn't happened yet but he said he'd keep me posted
https://utmindustry.com/utm3524/
creature.of.habit
Well-known member
Hi Jordan, just posting here 'cause I think my PMs are not going through. Just wondering if you got my replies to your July 28th message. Thanks!
(sorry to hijack the thread)
Hey, apologies! For some reason I wasn't getting notifications of your messages, but I just checked and I do indeed see the last two you sent. I'll respond to them!
creature.of.habit
Well-known member
Great! Sorry, really thought it was a website issue.
Question for the group: does anyone know how to reduce the size of a PDF without Acrobat? And what is the actual file size limit for the forum? I have the build guide ready to go, but it is too large to upload thanks to all of the pictures.
I'm not sure about the file size limit for the forum, but you could try a free online PDF compression utility. I just tried one called "PDF24", it reduced a 25mb file to 16mb.
Alternatively you could host it on google drive if you have that?
Brian Roth
Well-known member
.....or split into two or more smaller files?
Bri
Bri
