A #102 Attempt - First amp

[Vertigo]

I've been lurking here for five or six year, trying to absorb as much information as I can. It's slowly been sinking in, but over the past month, I've been spending more time tracing schematics and layouts in an attempt to understand them a bit better. It's making a little more sense now, but much is still in the dark.

I learn best by doing and last month I set out to build a SSS 002 mainly because RCColgan put a ton of work into documenting his build from start to finish in addition to sharing his CAD files, artwork etc...It seemed like low hanging fruit. I've got all the boards wired and soldered and with a little irony, I'm stuck on the thing that should be pretty easy for me to do...the chassis. A bit of mission creep set in. How to add a FET footswitch, should I try to add a d'lator to it? If I do, I can rework the chassis CAD file to my liking to make more room. I sort of got stuck and once I made the decision to go, my buddy with the sheet metal brake got busy with a flat track build for a show coming up in a few weeks. I've set that aside for the moment while Gregor runs on fumes for the next three weeks and thought I'd try something "easier" since I already have an ODS chassis and board set from Amplified Nation that I've had for the past year.

Until today, I thought I wanted to go for a #183. After a mishap with my van this morning created five hours of "free time" waiting at the dealership, I spent it listening to clips of the 102, 124 and 183. Norburybrook's and Chris Brown's builds of 102 sound so amazingly good, so that's where I landed.

But now I have questions

Specifically about the power section. I have a schematic drawn by mdroberts1243 (2010.11.07 Rev 1.0) that shows the caps in the power section which I'm assuming is the "classic" and not the "precision" supply (please correct me if I've goofed that up) and it shows 2) 220uF/350V, 2) 40uF/500V and 2) 20uF/500V caps while all the layouts that I've found for the 102, 124 and 183 apparently have the PPS scheme. I've also noticed that Norburybrook and Colossal appear to be using 4) 22uF/500V caps instead of the 40 and 20 (which I have not been able to find). I assume that the 22uf caps work but I don't know why they work and I have yet to find a thread that discusses it. Would anyone be willing to help me understand this a bit better?

Thank you to everyone here for your willingness to share. I build custom titanium bicycles for a living and while the frame builder community operates very much in the same spirit as what I see here, as a web forum, you all are incredibly sharing and polite, and that seems to be pretty rare these days. Thank you!

Sean

[norburybrook]

Sean,

I'm an ex racing cyclist so great to see a frame builder here

#102 is a great ODS to start with, if I could only have one it would be #102...I think....

the difference between the classic and precision power supply is the classic uses Axial caps and the precision mainly radial. High voltage axials are getting harder to find.

#102 used the classic power supply, and that's what i've used on my builds. It's a simple board to to make if you're doing it your self too. Chec out Martin Manning board sets in the files section, there's a pdf with the dinmensions, templates and component values there to download, everything you need

only variation I'd think about is perhaps to half the main filtering of the layouts 100w amp if you're making a 50w amp and same with the NFB value.


good luck with your build.

M

p.s, make sure you dont get polarised relays you'll save yourself some headaches.

[Guy77]

Hi Sean as others have and will mention the 102 is an awesome sounding amp. It is also my favourite!
Regarding the 40 uf in the power supply . I have built a 102 with the 40 uf and one with a 20 uf.

I found the bass sounds a little fuller with the 40uf and I ended up keeping the amp with the 40uf caps.
I believe it all comes down to personnel taste.
Either way you should have a great sounding amp which ever way you build it!

Cheers!

Guy

[Vertigo]

Sean,

I'm an ex racing cyclist so great to see a frame builder here

#102 is a great ODS to start with, if I could only have one it would be #102...I think....

the difference between the classic and precision power supply is the classic uses Axial caps and the precision mainly radial. High voltage axials are getting harder to find.

#102 used the classic power supply, and that's what i've used on my builds. It's a simple board to to make if you're doing it your self too. Chec out Martin Manning board sets in the files section, there's a pdf with the dinmensions, templates and component values there to download, everything you need

only variation I'd think about is perhaps to half the main filtering of the layouts 100w amp if you're making a 50w amp and same with the NFB value.


good luck with your build.

M

p.s, make sure you dont get polarised relays you'll save yourself some headaches.

Always nice to meet other cyclists. I raced mountain bikes quite a bit in the 90's, did a bunch of 24hr races and right around 2000 was getting some top 3 spots in the semi-pro class of observed trials competitions on the east coast. After moving west and 15 years of no racing I stepped into unfamiliar territory and started racing Super D (like a long downhill event that also has a little climbing) and was doing pretty well that year until I crashed on a fun ride and got pretty well injured. Going from 20mph to zero on a boulder is a hell of a way to slow down. Anyhow, I couldn't work for 8 months and used the time to learn how to build guitars https://ampgarage.com/forum/viewtopic.p ... 0&start=15 which helped me realize that there's more to life than taking care of my kids and doing everything else bike related.

I found the board template last night and found it curious, if only because I don't know what's acceptable to mix and I'm not willing to just slap some parts together and hope for the best. I can't make out the values of the 500V caps. It looks like both you and Colossal are using 22uF caps on your builds but I can't quite make out the labels in the photos either so I made my best guess and attached a screen shot below. As I said, I'm learning as I go, and am hoping not to make a mess of this.

Obviously I'll be standing on everyone elses shoulders here and will do my best to make a complete BOM with currently available components, a DIY file and a schematic of that file for future builders to use (assuming I succeed.)

Is this looking OK?

Screen Shot 2020-01-22 at 10.46.58 AM.png

[Vertigo]

Hi Sean as others have and will mention the 102 is an awesome sounding amp. It is also my favourite!
Regarding the 40 uf in the power supply . I have built a 102 with the 40 uf and one with a 20 uf.

I found the bass sounds a little fuller with the 40uf and I ended up keeping the amp with the 40uf caps.
I believe it all comes down to personnel taste.
Either way you should have a great sounding amp which ever way you build it!

Cheers!

Guy

Thanks for the input Guy. The amp you built with the 20uF caps, could you get enough bass out of it?

The last few amps I've owned were a Boogie Dual Rectifier Trem-O-Verb (20 years ago) and currently a MKV that's been in the shop for a while. I have an old PRS Custom 24, a Suhr Classic HSS and a Tele that I built last year and keep the bass knob turned way down or it gets farty with each of the guitars. I realize that these are very different amps, but also realize that I don't need a whole lot of bass coming through

[norburybrook]

I did my power section based on this

OTSFM50-ModernEagleMod.jpg

M

[pompeiisneaks]

...
I found the board template last night and found it curious, if only because I don't know what's acceptable to mix and I'm not willing to just slap some parts together and hope for the best. I can't make out the values of the 500V caps. It looks like both you and Colossal are using 22uF caps on your builds but I can't quite make out the labels in the photos either so I made my best guess and attached a screen shot below. As I said, I'm learning as I go, and am hoping not to make a mess of this.

Obviously I'll be standing on everyone elses shoulders here and will do my best to make a complete BOM with currently available components, a DIY file and a schematic of that file for future builders to use (assuming I succeed.)

Is this looking OK?

Screen Shot 2020-01-22 at 10.46.58 AM.png

That definitely doesn't look right.

I see at least two things wrong(nvm only one):

1. you've got the 220uF's in both with the double X of jumpers underneath, that's a no-no. You want to just have one jumper connecting the anode of one to the cathode of the other, for the series setup.
2. there's no connection from the end of that 220uF series to the next node. You'll need some kind of jumper between the choke node on the left and the 220uF node. Ignore that, I see you've set it up to run power into that node before standby, and then the standby connects it to the choke...

At a minimum, otherwise I think the rest looks right.
edit: sorry 2 was wrong
Edit2: NO I was still wrong, that's off to ground... Nothing to see here, move along lol

~Phil

[Vertigo]

That definitely doesn't look right.

I see at least two things wrong(nvm only one):

1. you've got the 220uF's in both with the double X of jumpers underneath, that's a no-no. You want to just have one jumper connecting the anode of one to the cathode of the other, for the series setup.

Edit2: NO I was still wrong, that's off to ground... Nothing to see here, move along lol

~Phil

Thanks for taking a look at it, but that was confusing. There's not really an X in the jumper wiring, one end of one of them is going to ground. So I'm good to go?

[pompeiisneaks]

That definitely doesn't look right.

I see at least two things wrong(nvm only one):

1. you've got the 220uF's in both with the double X of jumpers underneath, that's a no-no. You want to just have one jumper connecting the anode of one to the cathode of the other, for the series setup.

Edit2: NO I was still wrong, that's off to ground... Nothing to see here, move along lol

~Phil

Thanks for taking a look at it, but that was confusing. There's not really an X in the jumper wiring, one end of one of them is going to ground. So I'm good to go?

Yeah basically I had written it all up, and then kept looking at it and it suddenly made sense Sorry for the confusion, the ground being brought back up to the side with B+ just confused me for a minute. It looks good to me now.

Again, as I mentioned, ignore me

~Phil

[Vertigo]

Hey, I'm here with the full understanding that I know nothing but am trying to make sense of this. Any comment is going to prompt me to take another look at it and eventually (I hope) it'll end up correct before I melt anything.

[Guy77]

********************************************************************************************************************
[/quote]

Thanks for the input Guy. The amp you built with the 20uF caps, could you get enough bass out of it?

The last few amps I've owned were a Boogie Dual Rectifier Trem-O-Verb (20 years ago) and currently a MKV that's been in the shop for a while. I have an old PRS Custom 24, a Suhr Classic HSS and a Tele that I built last year and keep the bass knob turned way down or it gets farty with each of the guitars. I realize that these are very different amps, but also realize that I don't need a whole lot of bass coming through
[/quote]
**************************************************************************************************************************************

Hi yes the bass was fine with the 20uf caps. With the 40uf caps it was different for me in a nice way. The bass was bigger and rounder but not farty at all with the 40uf caps.
It may not be for everyone but definitely good to experience it so know if you like it or not.

Cheers

Guy

[norburybrook]

Hi Sean as others have and will mention the 102 is an awesome sounding amp. It is also my favourite!
Regarding the 40 uf in the power supply . I have built a 102 with the 40 uf and one with a 20 uf.

I found the bass sounds a little fuller with the 40uf and I ended up keeping the amp with the 40uf caps.
I believe it all comes down to personnel taste.
Either way you should have a great sounding amp which ever way you build it!

Cheers!

Guy

Thanks for the input Guy. The amp you built with the 20uF caps, could you get enough bass out of it?

The last few amps I've owned were a Boogie Dual Rectifier Trem-O-Verb (20 years ago) and currently a MKV that's been in the shop for a while. I have an old PRS Custom 24, a Suhr Classic HSS and a Tele that I built last year and keep the bass knob turned way down or it gets farty with each of the guitars. I realize that these are very different amps, but also realize that I don't need a whole lot of bass coming through

the 4.7(5) uF cathode bypass caps tame the low end in the pre amp so the amps are pretty tight in the bass anyway, that's one of the things HAD did to make the fender circuit less prone to farting out at high volume. The ODS loves high volume and doesn't fall apart like a fender super for example when you get into high volume territory.

I A/B'd my friends rig which consisted for 2x super reverbs and 2x deluxe reverbs all wired together dimed , thats a total of a lot of watts and 10 speakers the 50w #102 ODS into a 1x12 classic lead 80 speaker kept goig long after the fender rig had started to collapse sonic-ally. It was at that moment he got his check book out and said I have to have that amp!!!

M

[Vertigo]

I A/B'd my friends rig which consisted for 2x super reverbs and 2x deluxe reverbs all wired together dimed , thats a total of a lot of watts and 10 speakers the 50w #102 ODS into a 1x12 classic lead 80 speaker kept goig long after the fender rig had started to collapse sonic-ally. It was at that moment he got his check book out and said I have to have that amp!!!

M

My ears are ringing just thinking about that.

I'm using the layout from the Files section that Tony Albany did and also referencing another one called the "modified layout" because it has slightly better resolution and the LNFB Switch

Things to do:

Figure out how to wire the guitar input jack since I'll be using a small pot for the FET on the front panel
Figure out how to wire the third relay to make the FET foot switchable
If I have the PAB, OD and FET on a footswitch, do I need a DIN with more than five wire? I need at least six, correct?
On the modified layout, there are some caps on the FX send/return that are not on Tony's layout. What's that about?
On Tony's layout, there are 0.1uf 100v caps on the footswitch toggles for the OD and PAB..these are not on the "modified layout" What do those do? Pop suppression?

I'm making a DIYLC layout as I go through this. When it's done and correct, I'll share it in the Files section if anyone wants it.

[dimitris]

You can use even a four wire cable for three footswitches and their leds.
That's how i have my amp and it's working fine.
Check this thread:
https://ampgarage.com/forum/viewtopic.p ... 81#p393781

[norburybrook]

Vertigo,

Martin did this, check out the switchable FRET boost thread in the files section

FET_Relay_Schematic_r2.pdf

here's the footswitch, you can see the 1k resistors from the rectifier board are now on the footswitch so remove.

3 switch footswitch wiring.bmp

the caps/resistors on the send return are probably bright caps, up to you if you want to try them.


the footswitch toggle caps are probably to stop pops but I've never used them and had no problems.


M