Progress report

Doc B. · 22546

0 Members and 1 Guest are viewing this topic.

Offline vladimirwolfe

  • Jr. Member
  • **
    • Posts: 46
Reply #30 on: April 09, 2012, 06:19:56 PM
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



Offline rchristie

  • Newbie
  • *
    • Posts: 5
Reply #31 on: April 18, 2012, 02:14:25 PM
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

Rich Christie


Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9540
    • Bottlehead
Reply #32 on: April 18, 2012, 03:15:05 PM
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...

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline ET

  • Newbie
  • *
    • Posts: 3
Reply #33 on: April 20, 2012, 11:59:27 AM
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



Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9540
    • Bottlehead
Reply #34 on: May 01, 2012, 12:32:45 PM
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.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Spinifex

  • Jr. Member
  • **
    • Posts: 31
Reply #35 on: May 02, 2012, 04:45:20 AM
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.



Offline Pfenning

  • Full Member
  • ***
    • Posts: 138
  • My knockoffs
    • This is the place
Reply #36 on: May 02, 2012, 04:55:02 AM
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

Pfenning

Paramour 1's with c4s and iron upgrade, Foreplay II, Seduction with c4s, Crack (stock) and Foreplay III (waiting to be built), DIY turntable with Rega RB250 arm with Incognito wiring, Oppo DVD, Pi Stage 4's and DIY subs


Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9540
    • Bottlehead
Reply #37 on: May 02, 2012, 01:27:09 PM
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.
« Last Edit: May 02, 2012, 01:31:10 PM by Doc B. »

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline dbishopbliss

  • Sr. Member
  • ****
    • Posts: 287
Reply #38 on: May 03, 2012, 03:24:14 AM
I like the tube, but I might have to cover up the face.  Its sort of creeping me out. 

David B Bliss
Bottlehead: Foreplay I, Foreplay III, Paramour I w/Iron Upgrade, S.E.X. w/Iron Upgrade
Speakers: FE127E Metronomes, Jim Griffin Jordan/Aurum Cantus Monitors, ART Arrays
Other: Lightspeed Attenuator, "My Ref" Rev C Amps, Lampucera DAC


Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9540
    • Bottlehead
Reply #39 on: May 03, 2012, 04:29:53 AM
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.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline saildoctor

  • Full Member
  • ***
    • Posts: 140
Reply #40 on: May 04, 2012, 10:33:23 AM
I like it, he's like the genie in the bottle.  It's kind of hypnotic if you stare into his eyes!

Kerry Sherwin

45 Paramounts, 6SN7 Extended FPIII, OC3 regulated Seduction
Blumenstein Orca Deluxe / 2x Orca Subs
VPI Classic / ADC CD-100x


Offline Paul Joppa

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 5751
Reply #41 on: May 04, 2012, 02:07:31 PM
Kind of looks like the man in the moon...

"There is an inn, a merry old inn
   beneath an old grey hill,
 And there they brew a beer so brown
 That the Man in the Moon himself came down
   one night to drink his fill...."

(J.R.R. Tolkein)

Paul Joppa


Offline VoltSecond

  • Full Member
  • ***
    • Posts: 91
Reply #42 on: May 04, 2012, 07:35:52 PM
I can't tell from the picture, but can the tubes be wiggled out without taking the front plate off?



Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9540
    • Bottlehead
Reply #43 on: May 05, 2012, 04:55:37 AM
You have to open the cabinet to change tubes. The rear panel has also been designed to be open enough for the speaker to breath, but with small enough openings to keep small and large fingers away from the live terminals. The panels sandwich the wood frame between them. There are standoffs on the back of the front panel that have threaded ends that protrude through the back panel. They are clamped together with four wing nuts, so it will be easy to get inside to do mods, but it will also be rugged enough to pick up by the handle and haul around in your car trunk. The frame is reinforced with internal corner brackets. I think this is the most unique cabinet design I've come up with.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline pboser

  • Full Member
  • ***
    • Posts: 118
Reply #44 on: May 05, 2012, 05:15:53 AM
Kind of looks like the man in the moon...

Reminds me of the Honeymooners moon.

Peter Boser