• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

DIY Combo

Emanuel Apascaritei

Emanuel Apascaritei

Sep 12, 2009
2,549
871
Madrid, Spain
#1
hi,

I have a little Warwick 30.1 combo amp. It´s ok for what I need but it´s too heavy and I have to travel by subway and train.

I was thinking about the Phill Jones amps wich I think the design is perfect for what I need, but I don´t have the money to buy one.

so i started to do my own suitcase combo amp.

Components:
-Sony car amp, powered by a 500 watts pc supply
-Behringer little mixer,
-2x6" JBL (made in USA) drivers
-2x Sony tweeters

I have drown a sketch wich you can see in the picture attached
 
#5
I'd guess the behringer mixer act as a preamp.

I have doubts about that part though. IME those behringer mixers are noisy and finickey about input volume. Wouldn't it be better to use something more bass oriented? I doubt the eq will be very usefull for bass too.
 
#7
Matthijs said:
I'd guess the behringer mixer act as a preamp.

I have doubts about that part though. IME those behringer mixers are noisy and finickey about input volume. Wouldn't it be better to use something more bass oriented? I doubt the eq will be very usefull for bass too.
Click to expand...

as for eq, I don´t use it much so with those two shelfs is more than enough for me.

As something more bass oriented, why?

I won´t use more than 30 db of gain...wouldn´t worry about the noise. And I won´t use in studio envirement. For this purpose I have a UA La-610 wich is good enough.
 
#9
I was thinking something more bass oriented because of the eq and because of its input sensitivity and impedance. Ime when the input signal isn't an exact match its noisy in a way thats unpleasant outside of the studio too. But maybe that was just my bass or that particular behringer
 
#10
Matthijs said:
I was thinking something more bass oriented because of the eq and because of its input sensitivity and impedance. Ime when the input signal isn't an exact match its noisy in a way thats unpleasant outside of the studio too. But maybe that was just my bass or that particular behringer
Click to expand...

yes, there will be a impendance missmatch. If I plug a passive bass maybe I´ll have to use a little passive DI. Though I already plugged basses directly in little mixers and went ok.

The fact that I prefer a little mixer is that I can plug more things in it and use it as a little monitor.

It´s hard to explain. This amp is build for my necesities because I couldn´t find an affordable amp for my needs. And I already had the components...I only had to buy the carpet (it will be carpetened), the grill wich you see in the last picture (all the paint work was done by a friend of mine) and the mixer (wich costed me 33 euros).
 
#11
The con to this, as I see it, is that the PJB drivers are custom units with a large amount of excursion. Thus they can go low. I doubt the JBL drivers will compete.

I am also concerned with the use of a computer power supply. Using just the 12V output you will not be able to garner the whole 500W the supply is rated for.
 
#12
BassmanPaul said:
The con to this, as I see it, is that the PJB drivers are custom units with a large amount of excursion. Thus they can go low. I doubt the JBL drivers will compete.

I am also concerned with the use of a computer power supply. Using just the 12V output you will not be able to garner the whole 500W the supply is rated for.
Click to expand...

I´m pretty sure the PJB drivers are better and have larger excursion that the JBL. But the goal of this amp is not to compete with the PJB. One day when I´ll have the money maybe I´ll buy the PJB.
I´ve heard this speakers and can go really low, belive me. Don´t have a freq chart but as far as my experience testing all kinds of speakers (mastering monitors included), it can reach 33-35hz well....
My worries are not about how low can they go....but in the other side of the spectrum, the highs. There I´m a little blind because I didn´t test them with tweeters....

The amp is rated at 2x50 wats rms, and I belive the power supply will be more than enough...it´s a trial and error....

It´s a fun projetc....if something doesn´t come right....At least I tried it
 
#15
Interesting.
I was considering doing this myself.
Do you have the mods for the PC power supply?
I think the fan noise for the PC supply will be quite loud no?
Is it a tuned cabinet or just a box?

Best regards

Tee.
 
#16
teesquared said:
Interesting.
I was considering doing this myself.
Do you have the mods for the PC power supply?
I think the fan noise for the PC supply will be quite loud no?
Is it a tuned cabinet or just a box?

Best regards

Tee.
Click to expand...

It´s a tuned box hehhehe...I´ve made the bass reflex wholes at the bottom of the box, and the power amp will seat at about 4 cm from the wholes causing like a tunnel. (it´s hard to explain so I´ll take pictures and show you)

the power supply has just one 12" fan, it will do less noise than a bass amp with fan.
As the power supply has lots of rails, I´ll use the 12v CPU rail wich is the most powerfull and can drive the amp without problems. The rest of the rails I will cut them down directly from inside the power supply.
I´ll have to install the power botton too...it´will be on the rear pannel.
 
#18
Sorry, no pics yet, I had arrived very tired yesterday from work and I only had time to test it out for few minutes with my G&L and Jazz.

The sound is very hi-fi (that was one of the purpouse), it can get loud, and doesn´t lack bass at all.
I thought I needed a d.i. for the jazz (passive) but for my surprize it didn´t need it. The jazz was sounding precious, I could hear all the details and colour of the strings, and the bottom end was defined, full and round. The G&L was, in passive, round and full; in active was agresive and not so round, but well defined.

Pictures are in the way, it´s a promise
 

Latest posts

Top Bottom
Back