New 100W Build - pics and a few questions

[dogears]

Tip 2:

Try 2X220uf caps in the power supply. Dumble was keen to using big caps on the real deal amps of this era. Experience as he designed and not based on an internet layout not based on the real deal.

Then after trying it, pick which you prefer.

[talbany]

The wife bought me one of these chassis for Christmas for a personal build and built a 100w 700volt Music man Iron on it.. Amp was killer.. Robbie Flint is using it now on his summer tour with Alan Jackson.. WHAT a country player using an ODS style amp...Naturally we covered the Logo and doubt I'll get it back.. I liked the chassis for the money not bad.. The main issue I had was the lip on the top was not wide enough to install the threaded inserts to mount the damn thing so I had to build rails inside the cab to support the big transformers..Which actually worked out well.. Amp slides right out.. I do recommend you doing this if you get his chassis...I had no problem with the screening job..



Tony VVT

[wjdunham]

Tom, the amp was fine with humbuckers, now it's fine with single coils as well.

I have 4.7ufs bypass on everything except the second V1 stage, which is 10uF, I'll try upping them to 10 all around and see what happens. This one is pretty close I think, I have been listening to that clip of the Bludotone amp that was just posted, and a live version of Room 335, which I consider to be a benchmark. The smoothness is there, just missing a bit of bite or it's a bit too thin on the mid range notes, first string A through second string E notes, got a nice bite with the upper registers. Maybe those bypass caps will be the ticket here. No mud or flab in the bass. I'm also going to try bypassing the OD entrance cap as some have recommended on another thread recently.

The bass cap is a 225P 400V 102K. Most of the amp is 225P, a few 6PS 600V.

[wjdunham]

dogears, I assume you mean try replacing the first filtering stage 100uf caps with 220uFs?

The silkscreen on the thailand chassis is fine, just the hole sizes were slightly off, but nothing too difficult to fix. I had to put rails in the chassis as well to support the tranny weight and get it mounted properly, although it's been on the bench more than in the box.

FWIW, I bypassed the OD entrance cap, hard to tell a difference. The Les Paul, which was always a little heavy on the bottom end, is borderline now, the Strat sounds great, and that Ibanez Jem I have really sounds great. I'm going to leave it for a while, I'm playing in a small room so it's hard to get a good feel for how the low really sounds.

Tony, that's a nice looking clone. Is that just home depot type aluminum strip lining the top part?[/code]

[dogears]

Yep... The first stage. Use 2X220uf.

Also, only use the big bypass caps on V1. Leave the OD at 4.7uf.

dogears, I assume you mean try replacing the first filtering stage 100uf caps with 220uFs?

The silkscreen on the thailand chassis is fine, just the hole sizes were slightly off, but nothing too difficult to fix. I had to put rails in the chassis as well to support the tranny weight and get it mounted properly, although it's been on the bench more than in the box.

FWIW, I bypassed the OD entrance cap, hard to tell a difference. The Les Paul, which was always a little heavy on the bottom end, is borderline now, the Strat sounds great, and that Ibanez Jem I have really sounds great. I'm going to leave it for a while, I'm playing in a small room so it's hard to get a good feel for how the low really sounds.

Tony, that's a nice looking clone. Is that just home depot type aluminum strip lining the top part?[/code]

[Structo]

I recently upgraded my D'Lite to F & T filter caps.
Don't know what I was expecting but they look cool....

Then on a whim, I piggybacked the old two 100uf caps on top of the new 100uf caps.

Didn't really notice much, maybe a little tighter on the bottom.

[talbany]

Tony, that's a nice looking clone. Is that just home depot type aluminum strip lining the top part?

Thanks!! That was a fun build..I could never get tired of building those..
I don't do the ordering here just go in the back and pull what I need.. I think we got that at Mcmaster Carr..Although any aluminum strip will do.. The key is polishing it.. Mothers alloy mag wheel polish works pretty good..with some time a few coats and some elbow grease you can get them to shine like mirror...I also had some old Fender alum.tube shields I polished for it that is also a nice touch.

Then on a whim, I piggybacked the old two 100uf caps on top of the new 100uf caps.

Didn't really notice much, maybe a little tighter on the bottom.

Tom
You won't really notice the difference in tone feel of the cap increase until you start to really get the output section thumpin..Then you can really tell the difference..F&T's nice caps.. Run that puppy up you'll feel it..


Tony VVT

[wjdunham]

Waiting for my 220uF caps to come in. I put the 10uF on the CL1, it moved things in the right direction, but subtle. It seemed to have a bigger effect on the OD than on the clean channel itself, there's a wide range of sounds now depending on how the drive level is set. I get some nice sounds with it set at 3 and the master turned up, which a little thin before the change. I completely removed the OD entrance and I have no problems with OD bass. There's a very big clean bottom end, I'll have to see how it sounds with the full band before deciding if it's too much, I suspect not. With the .02 CL2 coupling cap it sounds great with all my guitars, fattest strat sounds I've gotten out of any amp. I'll post some clips when I get a chance, I'm really interested to get some feedback on the tone.

FWIW I'm using a 2x12 open back with EVM12L Classics for most of the evaluation. I'm using a Hammond 1650K OT, which is intended more of for HIFI application. It's pretty large, and has a frequency response down to 30Hz. All this is with the poweramp switched to 50W, where it sounds better. I'm guessing that the bigger caps will help the 100W setting sound better.

As of now, the preamp and poweramp are #124 except the .02 CL2 coupler, power supply will be close when I get the big caps. There's a lesson in there somewhere

[wjdunham]

Here are (very rough) clip from my ODS100 - Thanks for everyone's help - it's pretty close now to #124 schematic with a built in DLator. The biggest change was adding a separate supply for the DLator, so the voltages are now as documented here, I upped the cathode voltage in the DLator also. I upgraded the first stage caps to 220uf's from 100uFs since this a 100W amp, removed the OD entrance filter, both V1 cathode caps are 10uf, and I tweaked the treble bleed a bit. Everything recorded with an SM57 close mic'd in the middle of a EVM12L classic. I have a EH holy grail reverb in the loop and that's all for effects. Clean vol, bass, mid, treble all set at 4, OD level at 5, ratio at 2, master 2, presence 2 - PAB on the whole time. just a slightly loud bedroom level. Playing an strat using neck pickup except the end where I switch to the bridge.

I'm pretty happy with the tone, I'm interested to see what other's think. This has been a very rewarding project so far.

Bill

[odourboy]

I'm not sure if it's due to the lossy MP3 or some effects you're adding or what, but I was noticing some 'rain barrel' sort of phase distortion in the recording that detracted from a solid evaluation. But that aside, sounds good!

[wjdunham]

I suspect that's from the stereo and/or MP3 conversion, if you are referring to that slight "phasing" sound. I'm not using any effects other than the reverb.

[Bob-I]

Sounds great.

I see a lot of posts where a change is made and the conclusion was that the change was subtle. Awhile ago I compared my own amp to an identical one I built for a friend. When they were built they sounded identical but I've applied several tweaks that resulted in subtle differences. The comparison was like night and day. Thes subtle adjustments sometimes really add up to major differences.