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I have joined the Dark Side (well not really)
- Thread starter Psycho Bass Guy
- Start date
billfitzmaurice
Commercial User
- Sep 15, 2004
- 16,860
- 278
- 76
- Disclosures
- Owner, Bill Fitzmaurice Loudspeaker Design
Ya, I liked Psycho, but he made me look even keeled, and I'm anything but 
Still, I think it's a bummer he was booted. Always had great info.
Still, I think it's a bummer he was booted. Always had great info.
Hey if we can still put up with "some" of the condescending remarks of a certain person a couple of posts above? PBG and I had discussions, not really "fights" of any kind and you could depend on a response to a direct question instead of him putting you on ignore. 
Funny, I almost resurrected this zombie thread yesterday too. I have a couple of 400's and after several years finally bought a nos tung sol 12au7 this weekend. It sounds great. Lowered the baseline noise of the amp by 50% while at it
I tried this when I first got my 400+ and after swapping the original 12AX7 back-and-forth my conclusion was it simply sucked most of the meat off the bones of the amp. Now that I've had the amp for almost a year maybe I'll give it another shot.
I came to the same conclusion more or less- though I had been playing my 400+ for years happily when I heard about the mod so I was pretty biased. It did smooth out the response considerably, but that wasn't a good thing for my uses at the time. I did like how it made the Master Volume much less touchy though.
Yep, I too really miss Psychobassguy. His knowledge was a real asset to the Talkbass community. I rate him right up there with JohnK, Jimmy M and Tombowlus. He had a clear opinion, real experience and wasn't afraid to say what he thought. His technical knowledge was profound but he could state it in terms the layman could understand. He was my first Talkbass hero back in the day. Any chance of bringing him back?
I appreciate being lumped in with those guys, but they are miles above me in their knowledge
- Aug 21, 2008
- 10,386
- 253
- 68
- Disclosures
- Owner, SGD Music Products
When I got mine it had a fresh set of EH (or Sovtek, I forget now) preamp tubes (all 12AX7s) and Ruby power tubes. I bought it from an amp tech, so that's what he liked in it. He hates Mesa tubes.
I always found it to be clean and warm, if not a little on the soft side. It doesn't break up until I have it cranked up quite a bit. But once I get past a certain point, it's quite fuzzy.
I love the disscussion, and I am doing some research before picking up one of these beasts.
Anybody try adding negative feedback to the power amp? This guy did. looks interesting.
Did anyone post schematics for bias control? I could figure it out, but if it works for you I would love use what already works.Did you add current sense resistors to the cathode grounds? If so, what wattage should be used?
Anderbass, did you ever get your XLR di working? I was thinking the slave out pot may be a good place to start.
Anybody try adding negative feedback to the power amp? This guy did. looks interesting.
Did anyone post schematics for bias control? I could figure it out, but if it works for you I would love use what already works.Did you add current sense resistors to the cathode grounds? If so, what wattage should be used?
Anderbass, did you ever get your XLR di working? I was thinking the slave out pot may be a good place to start.
Please!!! Stop linking that video!!! That amp still had the exact same problem that the owner brought it to him for and eventually was brought to phoenix for me to look at and I found one bad tube, yes, one bad power tube.
That tech seems very knowledgeable and honestly probably knows more about the theory, etc than me but he didn't even have a cabinet to plug it into to listen to what it was doing and missed the obvious problem.
Look up my channel timv76 on youtube and I have a few vids of when I fixed the amp correctly.....
Here's number one:
Did anyone post schematics for bias control? I could figure it out, but if it works for you I would love use what already works.Did you add current sense resistors to the cathode grounds? If so, what wattage should be used?
Anderbass, did you ever get your XLR di working? I was thinking the slave out pot may be a good place to start.[/QUOTE]
That tech seems very knowledgeable and honestly probably knows more about the theory, etc than me but he didn't even have a cabinet to plug it into to listen to what it was doing and missed the obvious problem.
Look up my channel timv76 on youtube and I have a few vids of when I fixed the amp correctly.....
Here's number one:
Did anyone post schematics for bias control? I could figure it out, but if it works for you I would love use what already works.Did you add current sense resistors to the cathode grounds? If so, what wattage should be used?
Anderbass, did you ever get your XLR di working? I was thinking the slave out pot may be a good place to start.[/QUOTE]
Holy Psycho-bump! I miss PBG too...
edit: I had a 400+ for a couple years, I dug it but I could never really get over the fender tone stack. No midrange to speak of. I guess I'm a bandaxall guy for life...
edit: I had a 400+ for a couple years, I dug it but I could never really get over the fender tone stack. No midrange to speak of. I guess I'm a bandaxall guy for life...
Thanks for the video. Sorry to link it! Its one of the few pages google finds when searching. So, did you clip out the negative feedback? I am planning on a hardwired Fender 70's deep switch in the tone stack. Just a cap and resistor. That really boosts the low mids in my bassman I did this to the normal channel, since I never play with it off. I plan on putting an ampeg channel in the Bass one. BUT back to the 400. I am picking it up this week, I borrowed it a few years ago, but I am buying it this time. I will let you know how the DI works.
I also miss PBG...
And I also sold my 400+ some years ago.
I was never happy with my tone with mesa amps.
switched to ampeg, found the tone nirvana
- Aug 21, 2008
- 10,386
- 253
- 68
- Disclosures
- Owner, SGD Music Products
So the graphic EQ couldn't get that for you? I always found the 300+ to be very mid heavy, as is the case with most Mesa amps.
If you have the mids on 10, it's the full midrange. The bass and treble only boost. I never kept my mids all the way up because the amp got very honky. Just don't boost the bass and treble. The treble has to be under 7 or it takes away from the bass and mid control.
What cabinet were you using? My Mesa cab (with Eden speakers) is very mid heavy too.
And for he people wanting an SVT type tone, use channel 2, and boost the EQ at 250 Hz, since the SVT has a big hump at 250 hard wired in. Then roll off some of the very low end, because the SVT also has a bass roll off hard wired into the tone stack.
I always found my mesa setup (400+ and Powerhouse 4X10) lacking low mids, I couldn't make my P bass sounds right (for my taste). It was absolutely killer with my stingray or for particularly modern and/or aggressive sounds.
I tried to use the 400+ also as a power amp, receiving the signal from an SVP-CL... the sound was better but not quite right (again, for my taste/ears).
I guess the "issue" was also in the cab, too much lows, very aggressive in the high mids and very bright.
I'm sure that with an SVT410HE (my favorite 4X10 cab) the sound could be a lot closer to what I like, but at the end, if I search the ampeg sound, maybe it's better to buy ampegs and stick with them.
It took me some diggin just to find this thread. OK I suck at searching. After recently purchasing number three 400+ I wanted to give this a whirl. I have many NOS 5814A's laying around. 
I miss PBG too. This place has gotten way too politically correct the last few years which for me has translated in to bland no flavor pudding. It doesn't offend anyone but you don't get that hungry for it either.
I miss PBG too. This place has gotten way too politically correct the last few years which for me has translated in to bland no flavor pudding. It doesn't offend anyone but you don't get that hungry for it either.
