Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - RDV

Pages: 1 2 [3] 4 5 ... 13
Preamps and Effects / Re: Hiwatt-based preamp
« on: July 07, 2006, 09:35:50 AM »
Looking forward to sound samples.  :tu:


One things for sure guys, if you don't like the amp for guitar, it'll make a great all purpose power amp. I'm using them as stereo amps and guitar amps, and I'm working on one that will probably be used as a PA amp for single or duo-style gigs along with my rescued Mackie 1202VLZ.

The church my son plays in the band at gave us a burned out Peavey 2.6C which I'm putting two LM4780 chips(each wired in parallel) for a 100 watt per channel stereo amp. The heatsinks are already there as well as the on/off switches and circuit breaker. It'll be a cakewalk! I thought about fixing the amp already in it, but the circuit board had been on fire in two places! This thing will be sweet!


Amplifier Discussion / Re: SS poweramp as preamp
« on: July 05, 2006, 06:45:56 PM »
On the topic of small amps, I love my Dean Markley K-20X.  I personally haven't heard anything with as great a clean channel as it, and it has a really solid overdrive channel.  To tell you the truth, its basically my favorite overdrive sound.
It's basically a Distortion+ as a preamp, the DM OD channel of yours. I used to run mine into a large Peavey amp back in the eighties for my rock gigs.


It will be good for running direct perhaps, but may be funky into an actual cabinet. That's been my experience with cab sims.

I do, however look forward to your report.


Preamps and Effects / Re: Sparkle boost preamp
« on: July 03, 2006, 12:19:16 PM »
Gopher it!  :D


Preamps and Effects / Re: Sparkle boost preamp
« on: July 03, 2006, 10:28:03 AM »
Expensive FET in that one. The Mini-Booster and derivitives can be good candidates as well.

FETs just have that tubish vibe going for them, on the other hand though circuits built with them never seem completely clean.


Cool. I just wanted to be sure. I figured the 22k would be fine for the feedback resistor and all, probably adds a touch more gain.

I've got three amp projects going at once. The LM1875, a stereo LM4780, and another LM3886 guitar amp.



I just went through my parts and discovered I dont have a 1meg and I got 4ea 22k rather than 2ea 20k & 22k. Is this right? I wonder if that is supposed to be the values. I can get them myself but I want to make sure this is not what I should have received.


does anyone know how to modify a vox ad50vt to put out more wattage or maby even add a couple more tubes because ive asked a bunch of people and they all say that you cant mod ss amp which i know is bs so can someone help me???
Buy another one?
Just kidding!


Got mine. How did you separate your boards Joe?


Preamps and Effects / Re: Dr. Boogey Build report
« on: June 23, 2006, 09:15:44 PM »
Anybody that bought a PCB from OLcircuits for the DB before he pulled them and is having a problem, there was a 5nF from the 9v to ground by the second FET that was left out of gringo's layout that apparently is real important!

I used a .0047µF that I soldered to the rail and then to ground. I can now turn up all the knobs all the way with no SQUEAL.

I'm happy for the 1st time in days dude.

I came home from work yesterday in my hot van only to find a hot house. My air had gone out during the day and it was 95 out. They told me my air's shot and I was bummin' but this makes my day. I've been working on this for a week at least.



Preamps and Effects / Re: Dr. Boogey Build report
« on: June 23, 2006, 12:05:48 PM »
I worked on my DB all night last night and figured out the diagram I followed had a lot of incorrect values.  :grr

I replaced them all with correct values, and re-biased. I then had the classic sounds this circuit can make and much less noise, but the mid pot still squeals as soon as I go above 25%. I don't know why this happens. It calls for a 20k pot but I used a 25k. Would that make that huge of a difference? Where do you get 20k pots?

It's fun to play through though, but I'm scared to box it back up.


Preamps and Effects / Re: Dr. Boogey Build report
« on: June 22, 2006, 05:01:13 PM »
I can't get mine to stop whistling to save my life. It had me down last night, but I'm gonna get after it tonight again and try to tame the beast. It sounded great with everyting spread out, but boxed up there's almost no output at all but squealing. I'm about to rename it Dr. Piggy.

I'm gonna take it out of the box(1590BB) and twist the wires together for each pot tightly and try to route them better and see what happens. I may eventually end up putting the thing in an amp chassis where I can spread it out rather than try to box it up.

I'm also going to play with the bias a bunch. I'll try setting it real high, like around 6v each. I've got them all at 5v right now and it hardly works at all.


Just got my kit, Thanks Joe and Thanks Brian.

Just wondering on these things

-Which do I build, Whats the difference between the standard confiuration and the feedback capacitor

---> I used it. I don't think it makes too much difference.

-What rating and voltage should the on/off switch have and where does it goe i.e. before or after the transformer

---> A standard AC rated(110/220v) on/off switch will do and you put it between the AC line(hot) and the transformer(s).

-What kind of fuse, 2A 3AG or M205 or Ceramic Fuses.

---> Slow-Blo 3A should do the trick.



One other thing, I want to use the flipster as the preamp and power it from a different transformer, What is the safest way to hook two transformers up to one ac power supply.

---> Parallel. It sounds like you better do some reading before you start.

Also is this power supply regulated?

---> NO.

Please be careful.


Yes indeed thanks to Brian!

I listen to my stereo every day. Now if I could just get those darned speakers right!  :duh


Pages: 1 2 [3] 4 5 ... 13