The amp will be available in two versions – The standard 15-watt cathode biased model you have seen already, and a fixed bias model with adjustable bias trim pot. The fixed bias model will make about 18 watts of power, and it will cost a little more.
After trying a ton of different tubes in the amp Bruce has decided to go with JJ Tesla 6V6S power tubes and JJ Tesla 5751 preamp tube. These are different tubes than you heard in the earlier videos and they sound richer in the amp. The JJs have a bigger, browner tone. The amp is taking on the tone we were going for.
We may have a name: The Mission Delta Sonic 15. How does that strike you?
It is a small 1x10 amp driven by two 6V6 tubes in a tweed “Harvard” cab. It weighs only 25 pounds. It is meant as a performing amp. It will get you through most live gig situations without support from the PA. But when you need it, it has a great sounding line out jack on the top panel. Just run an instrument cable to the PA mixer and you are in business.
It has been fun to have you guys be part of the development process. Your comments and concerns have been very good. It is a better harp amp because of that.
Whats the difference between cathode and fixed? I mean, why would I select one over the other?
I like the name. I would drop the 15, at first look, I thought it denoted a 15" speaker. "The Mission Delta Sonic" rolls off my tongue easier, but hey, that's me. Can't say I have ever heard of an amp with a name like this. Its has been fun watching this amp "evolve"here on the site. Best of luck to Mr. Collins with the amp.
Last Edited by 6SN7 on Mar 30, 2013 5:51 AM
Since you asked: I'm no expert, but I don't think amplified harp is especially associated with the "Delta," so the use of that term in the name of the amp seems a bit gratuitous -- but maybe I'm missing something (like maybe it's referring to the Greek letter?) Of course in the big picture, it ain't a big deal!
TetonJohn, when I was in Clarksdale and Memphis I saw lots of harp amp tradition everywhere I looked. Back n the day there was all manner of small harp amps used in the juke joints: Radios, phonos, tape recorders, and old tube PA amps such as Masco or Philco. It may have gotten more attention on Maxwell Street in Chicago where they used bigger, louder amps, but it was happening on the Delta, too. Check out the Delta Blues Museum in Clarksdale.
6SN7- Cathode bias will give a more compressed sound with a bit sooner break-up. Fixed bias amps sound a bit stiffer and punchier. The difference is the way they send electricity to the power tubes.
Cathode biased amps (like a Champ or Deluxe) have a more "vintage" sound for harp. Fixed bias amps (like Bassman or SJ) have a more dynamic sound. Both sound great.
If you like a vintage tone I'd go with the standard cathode bias option. That is the way the amp is set up in this video.
I would suggest the name" The Delta Mission Sonic", It's a small change but it turns the name into a statment of intent, IE it is the mission of this Amp to give that Deep Down Delta blues tone that we know you are looking for,and you are still incorporating the "Mission" name.
