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Messages - lapsteelman

#1
I put other... what about something with a bit more power? I've built quite a few of the amps in Craig Anderton's Projects for Guitarist (TDA2003/LM383).. much more volume and headroom.. I power it with a 12 volt wall wart.. I know those chips are obsolete, but perhaps there is something comparable still in the pipe line...

Either way, great idea!

#Solidstate4life
#2
Amplifier Discussion / Re: Polytone 102 Tremolo
February 01, 2019, 12:04:00 AM
The circuit with the photo resistors  (U3A and B)  looks more like a simple phase shifter...   The first thing I would check is to make sure the lamp is flashing.. perhaps it's as simple as a burnt out lamp?
#3
Amplifier Discussion / Re: Hotone Nano Amp Heads
January 07, 2019, 11:17:20 PM
Scrolling through I saw this post from awhile ago... I believe there was discussion about these on Freestompboxes.... I believe they use the TDA2002 or TDA2003.. Fun little amps!
#4
Schematics and Layouts / Re: National GA920P Schematic
January 13, 2018, 11:42:55 PM
Haven't posted in awhile, just wanted to chime in and say a guitar player I was playing with got his hands on one of these.. I think he put a couple different speakers in the cabinet... but it sounded fantastic! REALLY great surf tone..
#5
Pretty sure it was from 93 or 92, and I think the cover was yellow. These are the things that stick in my brain all these years!  :loco
#6
I thought there might be some pack rats like me out there who had some back issues. I actually have a pretty good collection myself just not that issue. I'm sure a copy will surface on EBAY or I'll run across it somewhere.
#7
I kind of want to find/read the article more out of a sense of nostalgia than anything else.

I have never had a problem with the noise or distortion in the chip amps I have played with. ( except when I messed something up  :cheesy:). 

I think the article was geared toward HI FI.
#8
I doesn't surprise me that the concept might not be a winner, after all it's been 20 years and it hasn't exactly taken off like wildfire. I would still like to find the original article if possible and reread it, and it might be fun to put one together.
#9
I am pretty sure the LM1875 was the power amp. It could have been the op-amp in the feedback of the power amp. I remember it wasn't the conventional  pre amp/power amp configuration.

The muscle part was it basically gave you the low noise/THD of whatever op-amp amp you were using but with enough drive capacity to move a speaker to 10 to 20 watts.

I used to kill time when my girlfriend (now my wife) was in college by reading the electronics magazines in the library. At the time, I just couldn't get what they were doing in the circuit. I would like to revisit it.
#10
I have a vague memory of an artical in Radio Electronics magazine in the early 90's about using an audio amplifer IC (I think it was the lm1875) and a low noise op amp in an unusual way. I seem to remember that the power amp was in the feedback loop of the op amp, but it was almost 20 years ago so I could be wrong. I think it would have been around 1993. If anyone has a scan of the original artical or can link me to more information on this circuit technique I would greatly appreciate it.
I was pretty new to electronics at the time, but I think the jist was that using this circuit topology you got all the noise specs and  low THD of the op amp, ( which I believe was a ne5534) and the power amp IC was just acting as the muscle. (again.......20 years ago, forgive me if I got it wrong).

Thanks
#11
Amplifier Discussion / Re: Peavey Session 400 problem
January 09, 2013, 11:50:15 PM
You might want to do a search on the Steel Guitar Forum. This amp is popular with pedal steel players and they have a pretty good electronics section on the fourm over there.
I would be suspicious of the power supply caps also.
#12
Amplifier Discussion / Re: Speaker Enclosure
April 07, 2012, 11:55:47 PM
Quote from: erokit on April 04, 2012, 10:22:50 PM
My friend plays a pedal steel through either a Peavey 400, or a Evans. Both have 15" speakers. He and his steel buddies have preferred 15" for a full range sound. Typically an EV?

With the 10" or 8" do you get more of a mid-range honk?

I think pedal steel players typically have more strings in the low registers and need the extra low end. I just play 6 string C6th. My lowest string in that tuning is only a .36 or .38 tuned to C.  I am going for more of an old school Hawaiian sound.  A lot of the old student lap steel and amp sets only came with an 8 inch speaker.
I generaly turn the mids all the way down if the option is available.


#13
Amplifier Discussion / Re: Speaker Enclosure
March 26, 2012, 09:38:16 AM
I have played my C6th guitars through one of those Fender Acoustasonic amps and it had a real nice sound. Clear as a bell. I have played around with full range speakers on my own builds. It seems to be hit or miss. Some sound decent, others not so much.
I went through Scottys book and CD. It's a good place to start. I also got a Rob Haines C6th video.
I never could do much with Dobro G tuning. In the Arlen Roth video he does some stuff with that tuning. Lots of guys like it. ( For bluegrass it's almost mandatory  :))
#14
Amplifier Discussion / Re: Speaker Enclosure
March 25, 2012, 01:21:58 AM
I have a few lap steels. My favorites are Magnatones. I have a couple of Oahus too. I personally love to play in C6th tuning, but when I play out it's all Open E because it works better for the kind of stuff I'm ask to play. (mostly 80's and 90's radio rock). Not much call for Hawaiian music here in MI.
I  would probably go with a Jensen Mod "10 for a speaker because they are reasonably priced and I like the sound of the 8" one I have.
I love playing around with Audio amp IC's, and for C6th tuning you don't want much, if any distortion.  So it works out good. The ones I have played with ( TDA2002, LM1875, TDA7240) didn't even need a preamp, although some tone shaping other than just the tone pot on the steel may have changed that.
Heres a video clip of me playing steel. This is a Rickenbacker I used to have, I was demoing an overdrive I made.
http://www.youtube.com/watch?v=n2mI88xyXSo&list

I am trying to avoid woodworking and I am also trying to be cheap. :)
#15
Amplifier Discussion / Speaker Enclosure
March 24, 2012, 04:25:07 PM
I am wondering if anyone has use car style speaker enclosures with guitar speakers?

Such as these:
http://www.ebay.com/itm/1SL10-1-4-New-MDF-10-Single-Slot-Sealed-Sub-Woofer-Car-Enclosure-Speaker-Box-/120881267957?pt=LH_DefaultDomain_0&hash=item1c2515c4f5

What effect does the closed back have on the sound?