That is a beautiful selection of Amps! Did you ever sell your Champ?

Which particular OTS do you have, Ulf?

My Bluesmaster came pre-modded from Nik with the Mods I wanted, a switchable Sag resistor to simulate having a tube rectifier, and switchable resistors on the PAB. I also run a C-Lator with the tube switched to a low noise 7025. I don't use the Sag that much, and I tend to use the larger resistor value on the PAB (22M) as it gives more of a boost, and, much to my surprise, more of a clean boost (less middy than the standard value).

I have flirted with the idea of changing the slope resistor and bass pot to take some of the muddiness out, but as the amp and speakers have gotten some age and time on them, i have found that this is less of an issue for me. I thought about adding the London Power Scaling Kit to get more Power Tube /PI distortion out of the amp from time to time when i want it, but I have found that I can get it pretty readily by switching power tubes from my usual TAD 6L6WGC's to JAN Phillips 6L6WGB's and turning on the Sag resistor in order to drop the plate voltage down and be able to Bias em to a proper range (they are 23 watt tubes and running them in the OTS under full Plate Voltage is pushing them). Once i do that, i can turn the Preamp and master volumes up a bit and use the C-Lator to control the actual output and get some Output section saturation type sounds.

I have thought about adding a tube rectifier and making it switchable, but I think it would be more trouble than it's worth based on my latest rounds of A/B switching between having the Sag resistor engaged and disengaged.

I thought about adding some switchable bright caps, and a way to switch the HRM post OD tonestack in and out, but after the amp aged a bit i decided against that too

I have found that just by switching Preamp and Power amp tubes around and doing some knob twiddling, i can dial up pretty much any sound i want. The Bluesmaster is quite versatile, just as Nik said it would be.

That being said, i am considering a switchable LFB loop with some different values as the HRM's has no LFB loop and maybe trying some snubber caps on V2, as again the HRM's have none, just to see what the effect would be.

Very Nice!! I sure do miss my Les Paul, espcially now that I am realizing how much i dislike Strats through my Bluesmaster. Nice score Nairbr!

very nice! i am probably going to be doing my first build soon, either a tweed twin or a prinzetone. i kinda wish i had built my bluesmaster now, looks like it was alot of fun! beautiful cabinet work, too!

Gregg

Very nice!! I was going to build something similiar when i was going the head/cab route. Looks very cool!

So, here's the deal. I already have a sag resistor that Nik installed in my HRM BM, but, I am still toying with the idea of taking that out, and  adding a tube rectifier and having it switchable like the Mesa Amps and Nik's own Stray Cat. I already have found a suitable PT and plan on adding a second 6v transformer for the relays, so i have that covered. My main concern now, is the filter caps. Various sources say that the maximum cap value for a 5AR4 is 60uF, obviously the filter caps for the OTS series a slightly higher value than that (200uF x2 in series, which should be 100uF, if i am thinking correctly). My question is this. If i do decide to do this (still deciding) first of all, will running the tube rectifier in to a slightly higher value capacitor cause any harm and if i do have to change the values will changing the filter caps to a slightly lower value to allow the use of the tube rectifier effect the filtering to such a degree that it will be that noticeable?

I got a shirt too!! too bad i'm too fat to fit in it....

That is beautiful! Nice work, Bryan!

i'd have to agree with Nik. After emailing him for several weeks, and originally planning on having him build me either a Plexi 50 setup to run 6L6's or a JTM45 (both to allow my faithful Sovtek Mig50 to retire), i happened to mention to Nik how much I missed my modded original Princeton reverb amp that had a modified tone stack and a master volume added, but sounded great just cranked. He suggested that since i was thinking about the Plexi 50 or the JTM45, that I would probably really like the HRM Bluesmaster, since it has a nice Blackface thing going on the clean side that sounds killer cranked (which it does), and with the post OD (HRM) tonestack on the OD side it would be very flexible and versatile, and indeed it is. The only thing I don't like about the HRM is that the trimmers are internal, so if you do decide you want to change your sound a bit, you have to drop the chassis, but so far, i haven't needed to tweek em much at all. I am thinking about putting concentric pots for the tone stack though, so i can easily adjust both the main and internal tone stacks, though, just a thought. I don't think you can go wrong with any of Nik's amps, though, and his customer service is top notch, and will do some custom options (within reason).

very nice!

Nik to the rescue!!!

Sounds great, Nik!!

i had the same idea alte one sleep deprived night, Tom, until Pickmaste reminded me about the 200+ volts going through that circuit! I can tell you that, at least in my case burning the amp in for 40 hours or so has helped a ton. Hard playing for hours on end, and then playing some good jazz thru at moderate volumes at night while i sleep has made a big difference both in the amp and the speakers.

sounds like an awesome idea, nik! any chance of having different tone stack options, not switchable, but maybe offering different versions of the mini ots, liek say, a bluesmaster tonestack, or an HRM tonestack, etc? or maybe a single 6V6 version?

i like this idea alot!

Bluesmaster 50w with 1/2 power, Sag Resistor (switchable), and switchable PAB resistors (standard and 22M) and C-Lator
Open Backed 2x12 Combo with 2 Weber 1265 Alnico with the "Pre-Rola" Treatment Process
Type of music: Blues, R&B, Rock, Acid Rock, some Jazz and experimental instrumental stuff
Guitars: Fender American Strat with standard pickups, wired for standard switching and series neck-middle / bridge-middle, Danelectro DC59, Epiphone Sheraton II

I just changed my output tubes back to JAN Phillips 6L6WGB's from the usual TAD 6L6WGC-STR shorties that i usually run and use different settings depending on the tone i want.
With the 6L6WGB's i don't usually use the Overdrive at all and use the following settings:

For Cranked Blackface sounds:
V1 & V2: ANOS GE Long Plate 12AX7 // V3: Mullard CV4024 "balanced" // V4 & V5 JAN Phillips 6L6WGB Biased @ 42.5ma
Bright: On
Deep: On
Mid Boost: Off
Rock
Preamp Vol: 10
T/M/B: 8/ 3.5 /4
Master: 10
Presence: 8
Cl-ator: Drive 12'oclock Bright off/ Input 5'oclock(full)/ Output: used as overall master bright on
This yields a great cranked Blackface fender sound, and the original reason i bought this amp, as Nik told me that the Bluesmaster was the most Blackface like amp he currently builds, but also has the added benefit of an OD channel.

For Clean Blackface tones, i can roll my guitar volume back or i can use the following settings

V1 & V2: ANOS GE Long Plate 12AX7 // V3: Mullard CV4024 "balanced" // V4 & V5 JAN Phillips 6L6WGB Biased @ 42.5ma
Bright: On
Deep: On
Mid Boost: Off
Rock
Preamp Vol: 5
T/M/B: 8/ 5 /4
Master: 5
Presence: 6
Cl-ator: Drive 12'oclock Bright off/ Input 5'oclock(full)/ Output: used as overall master bright on

This can give good blackface clean tones as well. Note that with the JANs the bottom is nice and tight, but also less present.

For "Classic" D Style Overdrive sounds:

V1 & V2: ANOS GE Long Plate 12AX7 // V3: Mullard CV4024 "balanced" // V4 & V5 TAD 6L6WGC-STR Shorties biased @ 41.3 ma
Bright: On
Deep: On
Mid Boost: ON
Rock
Preamp Vol: 5
T/M/B: 8/ 3.5 /4
Drive: 5
OD Volume 5
Master: 5
Presence: 8
Cl-ator: Drive 12'oclock Bright off/ Input 5'oclock(full)/ Output: used as overall master bright on
HRM T/M/B: 11 o'clock // 12 o'clock // barely on

I tend to used PAB and OD together all the time, so that the HRM tonestack is all that you hear. This yields a pretty good classic bluesmaster d-style sound

for Classic BM cleans , which is basically the same as above, but with some slight adjustments to compensate for the added bass of the TAD's
V1 & V2: ANOS GE Long Plate 12AX7 // V3: Mullard CV4024 "balanced" // V4 & V5 TAD 6L6WGC-STR biased @ 41.3 ma
Bright: On
Deep: On
Mid Boost: Off
Rock
Preamp Vol: 5
T/M/B: 6/ 6 /3
Master: 5
Presence: 8
Cl-ator: Drive 12'oclock Bright off/ Input 5'oclock(full)/ Output: used as overall master bright on

this yields a good classic blackface sound with added punch in the lower range like a vibroverb, superreverb, or twin. this configuration has the most clean headroom, and really doesn't break up much at all, even if you push the preamp volume up. i love how versatile this amp is!

Hope this helps!

*****EDIT: I forgot to mention, I changed the tube in my c-lator from the stock JJ 12AX7 to a 7025 (low noise 12AT7). This really simultaneously warmed and brightened up the sound, while cleaning up the overall sound quite a bit*****