Can you make some sound clips for us to listen to? Breaking/burning in the amp will ten to get rid of any high end brittle or harshness. While the Jazz mode is less gainy and in turn may seem like it is more clear, it's not an answer for an amp that doesn't sound good in Rock mode. You should be able to obtain great tones in any position on that amp.

Have you checked the bias and made sure all the tubes are functioning properly? Something doesn't seem right with the amp. Getting some clips for us to listen to will help hear if there's something wrong with the amp. You really shouldn't be having this much trouble with a properly working OTS. (well, assuming that the guitar is functioning properly)

Very cool. What color is the lower one? Hard to tell exactly.

Excellent as always. 

Here are links to the layouts of the BM HRM and OTS. Any amp builder should be able to decipher the differences. As far as JM mods. I pretty sure if you search hard enough between here and TAG you should be able to get enough info for an amp builder to figure it out. I know I have seen them discussed here somewhere, but don't have time to go try and find them right now myself.

http://www.ceriatone.com/images/layoutPic/OvertoneLayout/OTS-BM-50W.jpg

http://www.ceriatone.com/images/layoutPic/OvertoneLayout/Overtone-Special-V2.jpg

Hey nudefish, I saw your post over at TAG and was going to say the same thing. Nik did/does these mods. Contact him and ask. He's very easy to talk to.

I have the TAD 6L6 WGC STR's and find them in simple terms to be a very solid sounding tubes that are very similar to what a very good 6L6's should sound like IMO.  They also seem to be holding up well. The preamp tubes are probably a harder thing to narrow down. As far as production tubes, I used Tung Sol's, but, I hear good things about others too (Mullards, Shuguang) JJ's are very good tubes. I find them to be a bit too gainy for the most part for certain applications. I think that Nik probably sticks with them because they are the most predictable and reliable from batch to batch and probably gets a really good deal, price wise. Consistency is very important to a business. And like I said they are good tubes.

Then there's NOS. It's worth a try to get some preamp NOS and see what you think.

Like Plasticvonaband (Greg) said, I would start out with a good set production tubes to get a good baseline. Preamp NOS tubes won't completely break the bank.

I have a HRM 50, never played a BM HRM. From what I've read and also my experience with the HRM I would say that it is the most versatile of the two. But, like I said never played the BM

As far as mods on the HRM. The LNFB is more subtle, but very worth having. It's something that doesn't interfer with circuit when it's off. I have gone back and forth about adding snubbers on V2, but have decided against it everytime I think I'm going to try it. To me the no snubbers on the OD is one of the major differences from the OTS. I don't have the 3-way mid boost, but it seems like it's would be a good mod. The HRM defeat seems like a logical mod also, but I certainly would want to have the ability to have the HRM tone stack. I see many owners complain about the HRM tonestack, but I find it very useful and am happy with the PAB taking out the clean tonestack.

Basically, I can say for sure that you can't go wrong with the HRM. It's the best amp I've ever played. 

You're the Man, Nik. 

Hmm, I never noticed the manual doesn't mention it.

I just knew about it due to building the amp and knowing that pot was a push/pull with a bright cap.

I use them for varying degrees of tone change, especially with the C-lator and humbuckers. But they're also great for single coils too. I find they can be helpful as my strings start to go dead. Just enough extra sauce. 

Well, this will get you started on finding what your amp is all about.

http://www.ceriatone.com/Manuals/ceriatone%20hrm%2050w%20100w%20manual.pdf

One of the main differences between the HRM and OTS is that it has a second tonestack for the OD channel. So when you have just the OD without PAB engaged you're going through both clean and OD tonestacks. With PAB engaged the clean tonestack is removed. This essentially will give more gain since the load of the first tonestack is gone. Also, depending how the internal HRM trimmers are set the tone may change. This can all be adjusted to taste.

Other differences are no snubbers on V2 and either no LNFB or switchable LNFB on V1. There are also slight differences to the OD portion of the circuit, like a internal trimmer for the OD entrance. Most of this gives the ability to really tweak the heck of the this amp.

I have a HRM 50 and really love it. I just had someone over yesterday and was tweaking the knobs while he was playing a standard Strat and was getting some great tones out of it. It's the first time that someone else was playing and I was just sitting listening. It takes a little while to get used to the amp. He was a little intimitaded at how to set it up. Thus me doing it for him.  Best amp I ever owned. And I've owned a few.

You'll love it. I have the ET65/Veteran 30 combo in a 2X12 open back Avatar cabinet. It sounds awesome. WGS has great speakers. I thought about going with the Retro 30 instead of the Veteran 30. I'm happy with the choice. If I was going for a 1X12 the Reaper or Reaper HP would most definitely be on the short list. I'm pretty sure you will be quite happy.

Also, even though they sound great from the start, as they break in they get even better.

Beautiful!! I don't know how I missed this post before. 

 
Wow!! That's some death.

Ironically I have been following and contributing to a thread over at TAG  about tube quality and whether NOS was really as great as everyone thinks. (not making any assumptions about your tube) But there's one less NOS tube left in the world. Well....working anyway. Sorry for your loss. 
http://ampgarage.com/forum/viewtopic.php?t=16893

Ahhh...thanks Gregg. I never knew about this. That's not so bad. 

OK, I admit ignorance. I have no clue of what is meant by "wiring the deep switch correctly". What exactly is not correct?