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leonard d rock
Silver Member
Philippines
301 Posts |
 Posted - 07/18/2008 : 12:50:15
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hi guys.
i was reading an old 90's guitar player magazine and it was an amp special issue. one of the articles talked there about guitarists who occasionally use an acoustic-electric but doesn't want to lug an acoustic amp. the article said a direct box might IIRC "modulate a piezo's high impedance to match the electric guitar amp's low impedance." it further stated that direct boxes can be passive and relatively easy to build.
so, does anybody here have built one or has a schematic to a relatively easy one to build? the one on the net are a little difficult for me.thanks.
regards, LDR
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DeFrag
Moderator
USA
3409 Posts |
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PaulH
Gold Member
535 Posts |
Posted - 07/18/2008 : 17:30:39
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If you want to buy one ready made, then the Sansamp Acoustic DI (now discontinued) is just perfect.
They can aslo be use for going direct to the PA with any instrument.
I use a couple for acoustic guitars/basses/mandolins, as well as electric guitars/basses etc.. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/18/2008 : 17:41:30
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Hi leonard d rock
Peizo's are a very high impedance device.
They are always run into an impedance Converter-Buffer.
they also need to have a lot of frequency compensation applied to them, as they are inherently
Very trebly, with almost no bottom end.
That's why you see the Bass Treble Middle - Presence & volume pots fitted to most piezo electro acoustics.
Or you can use an external box like the LR Briggs acoustic preamp.\the guy I went to see play this evening was using an LR=Briggs Acoustic preamp.
And it was a really well balanced & amazing to listen to sound.
I spent some time with him, talking about the Briggs & his Acoustic.
It had none of that annoying high end peizo snap & sizzle.
I was lucky & got off a few pics of his settings as well.
I have been interested in the LR Briggs for a while now, & you see them here in S/hand stores.
Basically you could build one as a hi to low impedance converter, but you will have to add a lot of tone control.
Look on the Web for FET buffer, as a FET has a very High imp. in, & can be set up for a low out.
There are a few good schematics & write ups on the web.
Let me know if you can't find them, & I will search in my archive for a link.
Regards Bob |
Edited by - Dr. Bob on 07/18/2008 17:43:09 |
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leonard d rock
Silver Member
Philippines
301 Posts |
Posted - 07/19/2008 : 11:31:28
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hello everybody!
thanks for the very quick and informative replies . i'll try to see if i can follow the schems and build one or have somebody build it for me, or buy a unit. i noticed tho that the out is balanced xlr while a guitar amps input is typically for 1/4 fone jacks. can i use the other 1/4fone jack (out) into the guitar amp?
thanks,
LDR
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 07/26/2008 : 18:46:39
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quote:
Originally posted by leonard d rock
hello everybody!
thanks for the very quick and informative replies. i'll try to see if i can follow the schems and build one or have somebody build it for me, or buy a unit. i noticed tho that the out is balanced xlr while a guitar amps input is typically for 1/4 fone jacks. can i use the other 1/4fone jack (out) into the guitar amp?
thanks,
LDR
hi leonard
personally unless your going for a particular type of sound i don't think you will get a good acoustic sound through a guitar amp as they are too midrangy sounding to get a proper acoustic tone even with a D.I box like you described..probably better off going through a P.A. or a powered P.A. speaker/acoustic amp....if your 'lugging' gear i'm assuming that you are gigging and a P.A is available...?? if your just messing about at home it might be ok....nothing puts me off more than my sound not being good especially with my acoustics and mandolin.... |
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August West
Bronze Member
USA
137 Posts |
Posted - 07/26/2008 : 22:44:25
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quote:
personally unless your going for a particular type of sound i don't think you will get a good acoustic sound through a guitar amp as they are too midrangy sounding to get a proper acoustic tone even with a D.I box like you described
I had the same thought. My elecrtic-acoustic sounds awful through my Fender amp. I hvae to say though that my Fender amp does NOT have a piezo input and maybe that is the issue more than the design of the amp itself but my gut is that it still would not sound right even if I corrected for that. |
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 07/27/2008 : 03:24:56
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| it's also down to the voicing of the speakers..for me acoustic guitars work best through full range speakers rather the something like a celestion V30 etc..... |
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leonard d rock
Silver Member
Philippines
301 Posts |
Posted - 07/27/2008 : 09:43:50
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hi guys,
i sometimes have gigs which calls for an acoustic for one or two songs only which i think doesn't justify another amp. i might go thru the PA but i plug the acoustic thru my pedalboard for some chorus and reverb. i agree that the acoustic sound best with full range speakers. well the search for tone continues...
ldr |
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 07/27/2008 : 16:44:45
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quote:
Originally posted by leonard d rock
hi guys,
i sometimes have gigs which calls for an acoustic for one or two songs only which i think doesn't justify another amp. i might go thru the PA but i plug the acoustic thru my pedalboard for some chorus and reverb. i agree that the acoustic sound best with full range speakers. well the search for tone continues...
ldr
Simple ...build another smaller 'board to go throught the P.A. with boss pedals of course.... ...only joking.... i'm in a similar prediciment at the moment with wanting to be able to switch between the guitars with the ability to still use the amp and pedals.... my solution is probably too much for you as it involves getting a couple of small active P.A speakers for the acoustic..i'm getting them anyway to split my rack into stereo off my Pod XT pro with the regular guitar amp running off the direct out on the pod in mono in the middle so they can double up as a acoustic amp i will just put the guitar amp on standby......the only thing is i will probably have to drop the BF-2 off my 'board as i need to make room for my GE-7 and the flanger is the pedal i use least....if i try to make a bigger pedalboard i will be sacked..... ......... |
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leonard d rock
Silver Member
Philippines
301 Posts |
Posted - 07/28/2008 : 02:27:35
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hi all, well i might try using a couple of samll PA speakers too. i saw the rivera sedona guitar amp which has two channels, one for electric and another one for acoustic with an extra speaker for it. anybody using it? looks expensive too.
LDR |
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leonard d rock
Silver Member
Philippines
301 Posts |
Posted - 08/15/2008 : 05:50:47
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hello everybody.
yesterday i bought a 10 meter microphone cable from an electronics store because it was cheap. it had an xlr plug on one end and a 1/4 mono phone plug on the other. when i arrived home, i tested it using my acoustic's preamp xlr out into my amp and i was floored by the sound. it was loud, full and dynamic with none of the piezo crackle i complained about earlier. this was the first time i used the xlr out of the acoustic, i used the phone plug out before since i didnt have a cable with an xlr plug on one end. i compared the sound coming from the fone plug out and there was really a big difference. i even plugged it into the pedal board and the xlr was way different from the fone plugs sound. can somebody explain this to me? i'm stumped since the other end is still a mono fone plug. of course i'm happy with the sound, just like to know what happened. i can now use the acoustic for a couple of songs without lugging another amp, i just have to bring that cable.do all acoustic electrics have both an xlr and fone plug out like mine?
LDR |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/15/2008 : 06:33:20
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| LDR!! That's awesome!! Congrats! |
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PaulH
Gold Member
535 Posts |
Posted - 08/15/2008 : 09:15:48
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If you watch Talking Heads Stop Making Sense, then you'll see David Byrne using his acoustic through his JC120.
Also, you'll see the only other stuff he uses is a BCB6 with a PSM and a 5 other Boss pedals in it. One is an old DM pedal I think, but you can work them out from the colours anyway!
Any young bands should watch it and see how to start your show from (literally) an empty stage!!!
Classic stuff indeed. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/15/2008 : 10:44:33
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Hi leonard d rock & Guys.
The 10M long cable will have some capacitance, & the longer it is the more capacitance it will have.
As well as a small resistance over its length.
I guess that this fact alone, has shunted some of the high end off your Piezo pickup and made it more tolerable.
Piezo picks ups have a lot of top end & sizzle if not EQ-ed correctly,
This normally happens in the on-board or off-board pre-amp.
And can sound pretty crap for this reason.
I guess you stumbled onto a very effective method of doing DI from a Piezo into an amp.
Can you please tell me/us what type-brand of cable it is?
You might find some printing along the length of cable.
Excellent bit of info & experimenting. 
Regards Dr. Bob |
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visserman
Platinum Member
1072 Posts |
Posted - 08/15/2008 : 13:04:30
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Many people have said great things.
I think most of us here feel that an acoustic cannot be amplified very well. The best sound you get with a mic.
If you can find a cheap small basspractiseamp buy it, as a bassamp is great for amplifying an acoustic/electric. Try find one which does have a line out so you need to bring two amps to your gig, but you could even use the bassamp all the time.
Why does bassamp better for this job? I think Franz and Bob went into it. It is all about frequency and speakers.
Oh the Sansamp idea someone mentioned earlier is good as well, very versatile tools for all kind of jobs really, worthwile investing in one. |
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Topic |
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direct box for acoustic into electric guitar amp
