Dumb question regarding one of Dr. Ika's mods:

Removing the .05uf cap at V1 -
Does that mean replace with wire, or break that connection?

Random thoughts:
I've had my OTS for about 2 years now and still not getting what I want out of it, though its getting close.
Currently running pine 2 x 12 diagonal cab with a pair of G12H30's. I found the EVM's to be somewhat sterile.
So I'm ready to try some mods. This amp is my first and only build.

I'm pretty happy with the OD tone, though I'm not getting the sustain/feedback thing much.
I have to play around with the PI, - I used the DCV method, but I'm going to try adjusting it by ear.
I'd like the clean to be more compressed, less stiff.
Some of Dr. Ika's mods seem to be the way to go.

Thanks again to Nik and many of you for helping me during the build.
I couldn't have done it without you!
Cheers,
Jon

I concur with the others - you need to break the amp in - and have patience.
The tones on most of the YouTube clips knocked me out, but I was quite disappointed with my OTS (non-HRM) at first.  After a little while, I noticed it seemed to sound better after being powered up for a couple hours.  After another little while, it was sounding pretty good without a long warm-up.
Then, when I thought it was broken in, I switched from Mesa 6L6's to JJ's and that made quite an improvement.
I haven't got a C-lator yet.  Instead, I wired up a 250K pot to make an attenuator. So I go Loop Out->my attenuator->Alesis Nanoverb->ART tube preamp.  To my surprise, this extra stuff in the signal path really improved things another notch.    With that extra stuff in the loop, the amp is smoother, and seems to want to go into that infinite sustain mode more readily than with nothing in the loop.
I've had my OTS for over 6 months now - played a bunch of gigs with it, and I'm still tweaking - experimenting with speakers, etc.  But I'm now very happy with the amp, find it very versatile and tonefull.   

Also, the gain structure is different from most amps. Nik says for max headroom, set the MV about noon and the Volume between noon and 2 o'clock.  Unlike most amps, the MV is situated before the Loop Out.  That's why, even with the MV down fairly low, but without my attenuator, the Nanoverb clipped easily - though the light stayed green.

On one hand, we all want amps that just sound great right away.  The OTS is not like that, but the reward for all the tweaking and patience is tone that you can't get from other amps.

I have 2 EVM12-L that I bought used.  One's a lot brighter than the other and technically sounds more 'right'.  The difference is quite large, and I wonder if the dark one is damaged, but it seems to have more mojo than the bright one.
Haven't been able to decide which is the clear winner.  They both record well.  I've used the brighter one live a few times and it sounds a bit hard at live volumes.  Sounds better to me at bedroom volume.  I'm going to try the dark one live and try to decide on one or other to use in combination with my G12-65.   (2 EVM's is too much for an old guy to schlepp.)
The G12-65 is light weight, plus it has a more organic sound than the EV's. I like it a lot.
The only reason I decided to try the EV's was to get more headroom.

One night I had to play without my pedals - straight into the amp.
I loved it!  Had a Dr. Z Maz Jr at the time.  I decided to get rid of all my OD pedals.
(Xotic RC, AC and BB - great pedals) and since the Z didn't have enough gain, started searching for a different amp.  Thats how I came upon the D-style.

For efx, I do the Larry Carlton thing - mic the amp -> efx -> another amp for the return.
My guitar goes straight to the amp.  Even as few as 3 or 4 true bypass pedals suck a lot of tone and responsiveness.  Even when they're not on - just in the chain.
When I plugged straight in - the guitar really 'came alive'.  When I need to tune, I pull the cable out of the amp and plug into the tuner.  Some efx, like wah, pretty much HAVE to be in the chain, but the less, the better.   Its not even the 'tone' that gets sucked out so much as the 'life'.

I noticed a couple of simple riffs I play that never sounded right until I ditched the pedals.
Now, all the nuances REALLY come through and inspire my playing in a way the OD pedals never could.

I've had my (self built) OTS for a few months now.  Originally put in MESA power tubes 'cause they were about the cheapest.  Figured they'd be good enough for the break-in period.
The amp sounded pretty good, but not as good as the UTube samples that persuaded me to buy it.

The other day, I bought some JJ's as I needed a set for backup.   Put the JJ's in, and WOW!
They were only $5 or so more than the MESA's but now the amp's sounding great.
With the MESA's, when playing distorted chords, it got downright ugly at times - harsh, lots of odd harmonics.  With the JJ's, I instantly noticed the tone was much thicker and smoother. Now those distorted chords ring like they're supposed to.
Maybe with some esoteric NOS/VOS tubes it might get even better, but for now I'm quite happy.

I have to agree with those who say this amp is like no other.  If you have one and aren't happy with the tone, stick with it and try some different tubes or mods or speakers.  You'll most likely eventually get what your looking for.  Its taken me months of gigging and tweaking to get myself into the ballpark. Don't give up!

The other numbers on the layout are just for identification purposes, so everyone knows exactly which wire is being discussed.

I found the wire-coloring confusing until I realized not to take it too literally.
What's this 5 inches of blue for???  Whatever you want.  A blue wire in the layout could be green in the photos, for example.  I thought each color had some specific role, but no, if Nik doesn't have blue, he'll give you purple.

Another tip mentioned elsewhere on this forum - don't cut-to-length the wires from the OT to the tubes, until AFTER you've connected them and turned the amp on for a test. If the amp squeals like a pig when you power up, reverse those wires. For some people, the layout is backwards.
SoundPerf says it has to do with the phase of the PT.

Other than that, if you follow the layout and photos carefully, you'll be fine.  Other than the OT wire reversal, my first build went perfect - and I have a lot less electronics experience than you.

As for how the amps respond to humbuckers vs single coil - it does seem the amps like humbuckers better - at least at bedroom levels.  My OTS sounds a lot different cranked up at gigs than at home.  At home, my humbucker guitar sounds fab, but when I try it at gigs, I always end up back on the Strat.  Most of the UTube vids are at lower levels.

Something else to be aware of, to get max clean headroom, you don't turn the MV up full and the preamp down, the way you would on most amps. Max clean headroom is achieved with MV at 11 o'clock or so, and the Volume at about 2 o'clock.

These amps are quite sophisticated and complex compared to most others.  It takes some experimenting to get the best out of them.

FWIW, I wired a ToneTubby Alnco and Celestion G12H in series and knew right away I didn't like it.
Can't really describe the difference, but when I put them in parallel, it just sounded 'better'.
In series, they sounded kinda stiff and lifeless.

I am a 1st time builder. The most complicated thing I've done before building an OTS is to wire up my Strat.
With help from Nik and this forum, my first build went without a hitch.  Most of my confusion was about what various pieces of wire were for.  When I grokked that this was somewhat arbitrary - the task became quite simple.  It was mostly a matter of following the pics and layout very carefully.  The next build will be a breeze.

IMO, printing a set of instructions - basically what to do in what order - would help 1st timers get it done with a lot less help from Nik.

So my vote, FWIW, is keep the kits...modify the support policy, which is way better than anyone has a right to expect.

If the kit hadn't been available, I wouldn't be playing through a Ceriatone now.

As for parts quality issue...
When I started researching D clones it quickly became apparent to me that Ceriatone's version sounded the best.
I've never heard a real D in person, but going by a ton of YouTube videos, I doubt if I could tell the difference between a real D and a Ceriatione.

Thanks Nik, for making it possible to have the tone I coveted for years.

I was using a G12-65. It just so happened a guy was selling one on Craigslist. He brought it to the gig, I threw it into a cab and wailed away.

Just finished my first gig with my new OTS50 and I loved it.
But, as others have noted, the low end is somewhat mushy at stage volumes.
Any mods available to tighten it up?
Thanks

I want to thank all the guys who helped me through my first build (0TS50).
When I first fired it up, it squealed like a pig and my heart sank into my shoes.
I would never be able to figure out what was wrong.  So I put out the call, and SoundPerf came to the rescue.
The OT primaries ended up having to be reversed from the diagram.

Left it on for a couple of days, then gigged with it tonite. It was inspiring.   Maybe I've just hyped myself up, but that was the most fun I've ever had playing a new amp.  A friend who's seen my band many times said it was the best he's ever heard me.
So  thanks again to the 'helpers' and those of you who are a noob like me, don't be afraid - just do it.

Thanks a billion, Chris. That solved it.
I'm actually hearing a guitar now!
AWESOME!!!
So now I just have to set the PI and bias and burn 'er in.

Thanks again - you made me a very happy camper.
Jon

Powered up using the Variac to slowly turn up the voltage.
Nothing went poof!!
But, when Voltage gets into operating range,  I get a high squeal - seems to be connected to the PI tube.
Tried different tubes.
With or without tubes in V1 and V2, when a tube is in V3 it squeals.
With no tube in V3 (with or without tubes in V1 and V2) - no squeal.
When I cut power, squeal fades out (doesn't end abruptly)

Any ideas?
Thanks
Jon

Thanks for responding.
I thought I read the Variac method was best, and I happen to have one.
I figured you would set it at a low voltage and measure at certain points to see if there was juice where its supposed to be and no juice where there's not supposed to be.
As I understand, the light bulb method just tells you whether or not you have a major short.

Is there a diagram or explicit instructions on how to do the bulb thing?
Do you do it with tubes in or out?  Speaker connected or not?

I'm ready and anxious to power up!
I have a gig this Saturday.
Cheers
Jon

Hi guys,

Going thru some of my (OTS) connections with a meter.
Measuring at the terminal strip where the Pilot Light and Heaters connect, there's less that 1 ohm resistance between terminals, and less that 1 ohm between either 3.15V terminal and the 3.15V ground wire.

Doesn't seem right, except that the pilot light (I'm guessing) creates the continuity between the 3.15V terminals.
But it doesn't seem right to be shorted (actually 0.3 ohms) to ground.

Is something wrong, or is this as it should be??
Thanx