Uproar ver.2 - modded Suhr Riot

madbean · Post by **madbean** » 07 Feb 2011, 11:50

Version 2 of the "Uproar" has an updated layout, changes to the tone section to bring it in line with the stock Riot design, and adds three potential mods: the Super-Duper Mid-Range Booster, the Presence mod, and the Facemelter. Everything you need is in the document below

Uproar.pdf

culturejam · Post by **culturejam** » 07 Feb 2011, 16:28

I can't wait to hear your thoughts on V2 compared to the actual Riot.

Vivi · Post by **Vivi** » 07 Feb 2011, 17:37

Any chance of a stripboard layout for this? I've got no problem building it on perfboard, but stripboard would be nicer and neater, no doubt.

JshDnls · Post by **JshDnls** » 07 Feb 2011, 17:44

This looks very promising! Well done Brian! I had a lot of hiss on my v1 build with the gain higher. Has this improved?

madbean · Post by **madbean** » 07 Feb 2011, 17:46

JshDnls wrote:This looks very promising! Well done Brian! I had a lot of hiss on my v1 build with the gain higher. Has this improved?

I didn't experience any unexpected noise. There will be a little a the highest settings, maybe, but really, it was not very noticeable. That was on the breadboard, too.

madbean · Post by **madbean** » 07 Feb 2011, 17:48

Vivi wrote:Any chance of a stripboard layout for this? I've got no problem building it on perfboard, but stripboard would be nicer and neater, no doubt.

I think there is a stripboard Riot already, correct? If so, it should be very easy to adopt to this version of the Uproar, should anyone want to. I don't really do those kind of layouts anymore, but someone else might want to take it on.

madbean · Post by **madbean** » 07 Feb 2011, 22:42

Okay I have CJ's Riot in hand and I've done a side-to-side. Nearly identical but not quite perfect. I was a little hampered by not having a 10kC or 10kA around, so I had to position the knobs on my build a little differently.

The main thing I noticed is that the Riot has more presence and the Uproar is a bit more woofy. Not in a bad way, but there is more lower mid content in the Uproar. The gain range matched up about 1:1, so I'm confident that is correct. The main difference ATM is the tone control and how best to match that to the Riot. In CJ's original tracing he had C2 (my schematic) listed as 22n, which is a huge bad ass bass rolloff at the top of the circuit. I listed mine as 47pF because that seemed more appropriate, and instead included the mid-range boost mod in the Uproar which closely captures that idea. After experimenting with the two different values, 47pF and 22n I was able to get the whole tone range of the Riot, just not with one cap only. So, it may be that C8 and C9 (my schem) need a little more tweaking to offset the difference, but I believe with my Presence mod it will cover the entire range without needing to do that, and in fact add more versatility.

Also, in CJ's tracing, I believe he had C10 (my schem) listed as 33n measured as 22n. This is incorrect: it's 1uF (yep, I've already taken the Riot apart). Actually, it's a Panasonic ECQ-V...looks exactly like the ones I have in my parts bin. So, I'll be making an update to the project file posted above to reflect that and also adjust the Presence mod in the Uproar accordingly.

The diode selection sounds a little different, but I also did not use the stock diodes indicated in the BOM. I used BAT41 in place of the germaniums, a Green LED instead of Blue for D7 and two RED LEDs for D8 and D9 (my schem). The Riot uses a C&K CT211 switch (On/On/On) so obviously the diode switching is a little different than the Uproar. Here's a link: http://www.ck-components.com/14429/ttoggle_31aug10.pdf/

I kept my switching different on purpose because those On/On/On ones are a bit harder to source than the average On/Off/On you can get anywhere. Smallbear does have them, though, so I might amend the documentation to show the two different methods of switching depending on what switch you can get.

Anyway, I can say that the Uproar and Riot are very, very close....probably 95%. I'm very pleased with how the Uproar sounds in comparison, and actually I cared a little less for the overall presence emphasis in the Riot. Both sound great, but the Uproar as it stands is not an exact copy, but a very good one indeed.

So, I will be adding one last revision to the ver.2 documentation to try to sort this all out. It's safe to go ahead and etch the pcb artwork as is, since I don't forsee making any changes to that.

Also, I absolutely want to affirm CJ's work on this. He did a terrific job getting this thing traced, esp. considering having to de-goop and deal with all the SMD stuff. The one cap value mistake is the only thing I found, and from experimenting with different sized caps in that position it actually makes little difference. So, save yourself $.20 if you want and use a 33n instead of the more expensive 1uF.

madbean · Post by **madbean** » 08 Feb 2011, 11:06

Updated below. This will be the last revision for now.

muhd85 · Post by **muhd85** » 22 Feb 2011, 13:32

Hello madbean, really appreciate your work really do!

I do have a question, since its hard to find an on on on switch, i decided not to put a switch. lets say if i want an led clipping according to ur schematic, should i just place led in parallel and connect to ground?

Also vice versa to the other clippings?

culturejam · Post by **culturejam** » 22 Feb 2011, 13:40

For some reason, I just now noticed your comparison notes. Well done, Brian.

madbean · Post by **madbean** » 22 Feb 2011, 13:44

D8 and D9 are connected to ground on the board, so you could leave all the other diodes off and the switch. Or, you could put any other combination of diodes in its place. Or, you could just jumper either of the two outside pads for the Clip switch to the middle to connect either of the two other sets to ground.

Keep in mind that this layout uses an On/Off/On SPDT.

kato · Post by **kato** » 12 Jun 2012, 17:09

madbean wrote: ...and two RED LEDs for D8 and D9 (my schem).

Brian, what were (your designation) D8 and D9 in the Riot?

I'm guessing from the parts list, since you list RED LED or 1N914 for D8, and RED LED for D9 that it was a combination of 1N914 and a red LED.

Am I reading that right? Or am I crazy?

nickthemen · Post by **nickthemen** » 12 Jun 2012, 22:23

C9 should be on pin 1 of the treble pot to the ground, not in the bass, low mid boost section, this will solve the highs problem !

kato · Post by **kato** » 12 Jun 2012, 22:45

nickthemen wrote:C9 should be on pin 1 of the treble pot to the ground, not in the bass, low mid boost section, this will solve the highs problem !

That's sort of what jymaze is suggesting by dropping the value of R7 down to 1k. You could try jumpering it altogether. Would be an easy hack for people who've already stuffed their boards.