D type amps are apparently designed to run with a full compliment of 12AX7 tubes.
After experimenting with a few different preamp tubes in my OTS 100,  i`ve come to the conclusion that a 12AX7 LPS in V1 along with 12AY7 tubes in both V2 & V3 produces some very warm & organic tones.
In the PI (V3) postion, the amp becomes very warm and smooth.
Overall volume needs to be bumped up a notch to compensate, but the tone difference is well worth it.
V2 12AY7 gives a smoother & warmer overdrive... less hard & grainy sounding than a 12AX7. Again, just adjust the OD gain trim to suit.
My amp has the OD trim on the rear panel, so it`s a breeze to adjust while experimenting.
Overall the amp becomes more open sounding, the tone is warmer & the OD is smoother.
If you love hard rock tones from this amp, 12AX7s are probably best, but for a warmer & more dynamic L Carlton type tone the 12AY7s are doing it for me.

Hey guys... interesting topic..!
What`s your method to drain off stored voltage in the caps once the amp is totally shut off.
I`ve read that the OTS will do this if you turn off the mains switch and leave the standby in operate position, while waiting an hour or two.
Does this sound right.. or do we need to earth the caps to the chassis...?
I do have a voltmeter to check & confirm any voltages in the caps.
Cheers..

No doubt it`s worth experimenting with these units in the loop, as you`ve had great results too.
I`m not using a *lator of any kind,.. just running the PB into a Nova reverb.. and they work perfectly together.

It`s great to get such good results.. especially with a strat..!

Hi there... You`re probably right about the twin tube acting as a tube buffer in the loop.
Have you tried the TT in the loop with a strat plugged in the amp..?
Indeed the Duncan PB in the loop has very good results for fattening up a stratocaster.
I get an authentic, warm jazz tone using the front pickup with the tone pot rolled back to around 6/7
And there`s no muddy or dull tone.. just warm, fat and plenty of balanced clarity.. sounding very PAFish.

Turning the strat tone pot to 10, you have a fat strat tone... and without any loss of the typical strat character.
Which is, IMHO.. quite an improvment over the usual strat sound.
To compare against the normal strat tone, all you have to do is flick the frequency filter back in the middle position.

The top postion on the frequency filter is very usable as well to fatten the tone, but with a little less 'fat' than the bottom position.

Cheers

After trying a Duncan pickup booster pedal in front of an OTS 100, I thought i`d try it in the loop.
The results are worth mentioning as a strat & tele can be made to sound alot fuller in tone.
The frequency filters on this pedal are the key to achieving this.. and there are 3 positions.
* middle position is standard with no frequency shift, but you can boost the signal if you wish via a gain pot.
*Top position is standard PAF type humbucker
*Bottom position is hot humbucker.

Using single coil fender pickups with the frequency filter on hot humbucker, and gain pot at minimum on the pedal, it`s possible to achieve a very warm  tone very similar to a PAF type humbucker.
It pays to run the master vol higher on the amp, while keeping the volume level on the amp a bit lower than you usually would.
This compensates for keeping things balanced from my experience.

There seems to be a few strat players that aren`t totally happy with the sonic results of this type guitar in the OTS.
From my experience, if you use single coil pickups and would like a warmer,fatter tone that is balanced in the frequencies, give this booster pedal a try.

Awesome help... Thanking you for that.. Cheers

I think you will find medium to high gain tube amps with an OD circuit don`t employ tube rectification.
Older/vintage low wattage amps used tube rectifiers, but i`m sure anything with an OD channel/circuit wouldn`t be best suited this.
I guess the simple reason would be.. vintage amps without an OD circuit already 'sag' when pushed hard due to the inefficient power supply of the older amps.
This could well be desirable if you were playing the blues through a tweed bassman, super,deluxe.. etc, but an amp with an intended OD channel needs a modern type power supply that will keep up with the demands of the amp.
Cheers...

Hi there.. Is anyone able to advise if the TC nova Reverb is eay to dial in for use in the effects loop..?
I see this unit is suitable for D type effects loops.

*Does the Nova automatically set the line level for best results when plugged into the loop, or does the user need to calibrate this function manually when using the Nova..?
Thanks alot..! Cheers...

That`s some good info..  Thanks Greg..!

Looks like the 70s D models sound very good with strats.
These circuits seem to have what`s termed the 'classic' tone stack.
Nik`s D amps to date appear to be high plate 80s & 90s models with the 'sky liner' tone stack.. which from my understanding tend to suit humbuckers better.
Can anyone enlighten us on the subject of the different tone stacks & perhaps high plate vs low plate D amps..?
Apparently, low plate models have a softer tone.

Would be interesting if Ceriatone were to offer a model or two with the earlier circuits.. ie Steve Farris, David Lindley, Lowell George etc.

Cheers..

Any information out there on the so called Robben Ford mod..?
Does Nic maybe offer this..?
From what I`ve read, there`s a power resistor instead of a choke in the power supply to induce more sag in the amp.

Very good question indeed..!
D-mble amps do have an inherint tone character that`s fat, warm, sustaining and "reedy".
The Bludo seems to have this in spades.. and i know what you mean about the clean signal and slight O/D touch sensitive growl that seems to occur simultaneously...!
I think this is part of the genius of the original amp designer.

Good pickups & an EV12L will no doubt benefit you`re overall tone,
BUT.. an original D-mble will still retain it`s tone character no matter what cab it`s plugged into.
And a novice will still be able to achieve that tone,.. it just won`t be fluid sounding like an experinced player.

My point being.. the 'amp tones' of this Bludo & an original D-mble are in the amp.
Having great pkups, speaker and fluid fingers are a bonus to the already unique tones in these amps.

I have an OTS myself and although it does display D-mble tone in one way or another, i must agree I can`t achieve that tone character you`re looking for.
You can try different pre-amp tubes and speakers etc, and adjust the internal trim-pots, but I`m not so sure what you`re looking for can be found in the OTS.

I contacted Gregor Hilden on his web-site & orderd an OKKO TwinSonic from him.
He demo`s these on youtube and I found the TwinSonic and Diablo (Higher gain model) to be VERY D type built in a box.
I`m very satisfied with it through the OTS as it gets that L Carlton thing no worries.
It cant do the simultaneous clean & slight O/D growl because that`s part of the original amp circuit, but it is Very D-mble like indeed.

For another example of  D-mble tone..  have a look on youtube
Dumble ODS-100 (Owner: Peterguitlerche and you will be amazed at the sonic character of this amp in both clean & O/D.
Once again you`ll hear that Reedy tone and clean-slight growl simultaneously..!!

Cheers.

Comparing the OTS to a Fender 'Blackface' in the clean department,  I`d think you`d have to get a good reverb unit happening on the OTS first.
Quite a big part of the blackface character is due to the classic reverb in the mix.

I`ve owned a super reverb & twins too and if you dial out the reverb, alot of what you hear changes. Maybe not sonically, but the overall character does alter.

My OTS sounds great and more fender like than anything else, but the OTS really does have its own thing happening in the cleans department and I do believe it`s probably a better tone than a Blackface clean,.. if you have a decent reverb unit on-board..!

The OTS has more transperancey to its cleans than a Fender in my opinion and the definition of the bass, mid & trebles are more pronounced and refined compared to the Blackface I think.

If you just love Fender BF cleans and reverb,.. then best you get one of those models and maybe drive it with a D-mble like OD pedal ie:  Zen Drive or the Okko 'TwinSonic'...!!

Cheers and good luck.

Haven`t seen any HRM BM sound clips as yet.
Would be most interesting to view..!

From the horses mouth too..!
That bit of information is very enlightening.

Thanks for posting that...  Cheers.