Progress report

I'm curious to see what you come up with for cabinet style.  I personally like retro-ish styling like the new Zinky Supro, Epiphone Triggerman or Tone King.  I recently built a 2x12 cab that I was thinking of doing something similar but ended up going with a traditional Marshall design.  Made it exactly 1/2 of a 4x12 straight cab.  Box jointed baltic birch, genuine fir braces, etc.
 
The prototype is fairly close to what the kit will be like. It's unconventional with the front and back panels being aluminum, but it follows our ideas of layout, and I think it sounds nice. I like that sort of vintage upholstered Jetsons TV look too. Unfortunately that would cost a lot to make.

It will be fun to see how builders will customize their cabinets. I imagine we'll see everything from bed liner to hand rubbed lacquer.
 
I have to admit to a funny (or is it tacky?) vision of the speaker cutout taking on the shape of the Bottlehead man. In all seriousness, though, I actually like the cabinet the way it is presented in the video, and already have some ideas of how I would finish it. The aluminum plate and wooden box setup common to all BH kits might work well here.
 
Dr. Toobz said:
I have to admit to a funny (or is it tacky?) vision of the speaker cutout taking on the shape of the Bottlehead man. 

Weeellll, that's actually what I've been working on...not the whole cutout, just a Bottlehead in the middle where the "beam blocker" is. I want to see glowing eyes...
 
Sent the link to an old guitar player in Portland OR and he likes the looks of it.  Maybe a new Bottlehead convert on the horizon.
 
For those of you who are coming by Bottleheadquarters for the open house this evening (4-7pm), I'll have the amp set up in my office with a Saga Telecaster kit guitar (seems appropriate). I won't play it - don't want to hurt anyone - but everyone will welcome to give the Tode a test drive, er, hop.
 
The Tode was well received by a couple of guitar players at our open house a week ago. In the past week I worked out the blocking distortion issue. It was simply a miswire. Once that was sorted I adjusted the global feedback a little to get the amp to go into overdrive at a bit lower signal level. Works better than ever now. I have an inexpensive single ended 12AX7/6L6 combo amp with an 8" driver I bought on ebay to get a feel for what is out there. In comparison the Tode does a much better job of delivering the player's articulation without getting dull or muddy, and the gain is enough higher that it is easier to go back and forth from clean to overdrive as you play. I really like the Weber ceramic magnet driver I chose too. Thought it would be a good idea to try other speakers that will fit in the shallow cabinet, so I have ordered a Jensen Mod8 to try as well. Since the circuit is reminiscent of some British amps and the Mod8 is supposed to have some British speaker character it might be a nice combination. I hope to see a sample of the production version of the output transformer later this week.

By the way, the Mini Strat I got last week sounds surprisingly good and the short scale is indeed much easier for my short, unskilled fingers. I've been watching videos of great guitar players who are known to have small hands. It's very interesting to watch their playing style.
 
Damn it Doc, will you quit teasing us and just release this thing! ;-) I mean, my credit card is vibrating.

Glad to hear the Mini Strat is working out for you. I checked out the Duo Sonics on eBay after I recommended you look at those and was surprised how much their value has risen over the past couple of years. Since no "real" person can afford a vintage Tele or Strat it's no wonder the Duo's are appreciating.
 
Believe me I am really trying to fast track this thing! I feel fairly confident that the next proto will be the final and we can go ahead. I know I keep saying this, but it's a rather unconventional design and I need to make sure I don't inadvertently screw the pooch through rushing it too much.

The next version might have a single level control and a bass control as well as treble...
 
Just pushing your buttons Doc! I'm amazed at how fast you went from the idea to a working prototype. As you've said, this isn't your average champ clone which is why we guitar slingers are salivating over the Tode. Forward into the past!

Doug
 
Doc, this sounds like it's going to be amazing!  How different would a design for bass guitar be?  Is that a totally different beast?

- Rich
 
Actually a bass guitar amp is a lot closer to a hi fi amp. Bass players need to get a lot of clean power. Might be one in the future, if I get inspired?

Meantime lots of fun stuff has been happening. The controls are now the brake, which is more or less the master volume (other volume control is at the guitar); feedback, which inserts a 50K variable resistor into the feedback loop to lessen or remove the feedback for greater distortion and gain; and the third control is now a variable resistor in series with the output tube cathode bypass cap. There is a small cap bypassing this that preserves the high treble. Rolling this pot on gives about a 15dB max scoop that curves from about 200Hz to maybe 4kHz.  Then you can roll off the top end with the tone control on your guitar if you wish.

Another way big improvement that happened Sunday was that I changed to the Jensen Mod8 speaker. Very nice speaker, much better bass in this box and a wee bit of mid scoop that helps to give a better balanced sound from a twee little speaker. The Weber I started with is nice too, but this Jensen happens to work better in this app. In fact it now sounds pretty close tonally to the 12" Eminence Legend I have been comparing to. The Weber may end up in an Electar 10 I bought when I started to investigate what's out there in inexpensive tube combo amps. The stock speaker in that Electar is mud!

Along with all this the little Mini Strat I bought is getting turned into a real guitar. I bought some Alnico V, slightly overwound Strat pickups on ebay. The seller sells the set for a ridiculously cheap $32, figured I couldn't lose trying them. Completely transformed the little axe, really Stratty now with a twangy bridge, quacking 2nd position and a nice big toned neck sound. Some Thomastik Blues Sliders in a custom even tension 11-48 set I put together are on there, a nice old .022 oil cap I had went into the tone control, a Yamaha 5 way switch replaced the 3 way it came with. Have a bone nut and some steel saddles coming along with some string thru bushings. I think that for about $150 I'm going to end up with a really neat little guitar that's fairly easy for me little fingers to stretch on. This whole new rig has me inspired and I've been practicing about 1/2 an hour to an hour every night. Maybe I'll be able to make it through a whole song some day after all! Think I'll try the 335 on the amp tonite. With a couple of guitars I really dig playing around with, might be it's time to sell my Teles...
 
Wow Doc, I am getting itchy now to see what the kit looks like.
My son has one of the small strats and they are fun. 
Like everyone else I am going to throw in my two cents and I fully trust you to do what is best
(although if the ideas are worthwhile, please run with them)
.
I would love an amp that has no box and the kit is the amp and sheet metal, possible option?
I can cut the wood box or put it in another amp box and mess with speakers, etc.
.
I see some small simple 2-3 tube SE guitar amps out there that allow tube rolling (emorysound?)
that can use multiple power and rectifier combos, and even allow rolling of the 12A*7's.
I would guess many tube geeks would love to roll their own to the maximum allowed.
.
thanks for your time.  Keep on the studio/home SE simple guitar theme, I can build it and i don't plan on
playing the paramount any time soon, but want something cool.
looks great.
Tim
 
More good progress this week. We did do a bit of backpedaling, a pretty standard part of the design process. After using the Jensen speaker for a while I found myself wishing for a little more top end, as it didn't seem to show off how responsive this little amp is. Went back to the Weber speaker and I liked the open treble, but felt once again that the crunch came in a little too abruptly. I have ordered a Weber with a different cone that, based upon the description, should be somewhere in between the other two speakers. Fingers crossed...

We are also trying a bit different approach to the mid scoop control, implementing a notch filter at the input. It will be adjusted with a switch to more or less emulate a Fender style mid scoop, a Marshall style one, and the third setting will be a defeat, no scoop at all.

We have refined the front panel design and it is out for quotes. We have tested the new output transformer and it has hit the spec very well, easily in same ballpark as a Champ output transformer in terms of inductance, and able to take a lot of current.

Today we are working up the layout for the next prototype and sourcing a few parts.
 
Doc B. said:
Actually a bass guitar amp is a lot closer to a hi fi amp. Bass players need to get a lot of clean power. Might be one in the future, if I get inspired?

That would be very nice. There's not that many dedicated bass guitar amplifier kits out there.
 
Thanks for the update Doc. I can't wait to see the next prototype and I like the sound of the mid scoop control. Is the brake still in the plan?

Pfenning
 
I think you guys will enjoy the new speaker grill. The 2" round part in the center, that the face is cut into, helps to reduce beaming. If we hit our numbers the kit should come out at around $599. That compares pretty favorably to what I perceive to be competitive amp kits.
 

Attachments

dbishopbliss said:
I like the tube, but I might have to cover up the face.  Its sort of creeping me out. 

I guess you probably won't like the evil clown version either.
 
Back
Top