Stereo 2030 amp for a jazz band

[svstee]

Well, I need an amp for my college jazz band. I always wanted a Roland JC, even before I played much jazz I thought they had the best clean tone ever. I have an idea vaguely sort of similar to the JC, two totally separate amps each running into a separate speaker, each voiced a little differently for a nice stereo effect. I came across this
http://eu.st.com/stonline/products/literature/ds/1459/tda2030a.pdf
and my tentative plan is to build two poweramp sections with these, using something like this
http://www.runoffgroove.com/tonemender.html
for each of the two preamps.

I found these, will they work for what I want to build?
http://www.generalguitargadgets.com/pdf/ggg_20x0_amp.pdf
http://www.generalguitargadgets.com/pdf/ggg_bipolar_ps.pdf
Any AC non center tap step down transformer with a secondary of 24-30v will work, right?


Here is my current bill of materials, am I forgetting anything?

(for poweramp)
Resistors (1/4 watt rating)
1 – 4.7 ohm ½ watt
1 – 680 ohm
2 – 22k
ICs
1 – TDA2030 or TDA2040 ammp IC
Capacitors (minimum 20 volt rating)
3 – 0.1uF film
1 – 1uF aluminum electrolytic
1 – 22uF aluminum electrolytic
2 – 220uF aluminum electrolytic
Other
2 – 1N4004
24 gauge stranded wire

(for bipolar supply)
Capacitors
2 – 1000uF Aluminum Electrolytic
4 – 0.1uF film
Other
2 – 1N4004
3-way power jacks/connectors
2 – Regulator Heat Sinks
Thermal Compound (heat sink grease)
22 gauge stranded wire
AC Cord/plug
2 – sets of nuts and bolts to bolt down the
regulators or to bolt the regulators to the heat
sinks.
heat sinks
110v in 24v out transformer (1.25A okay?)
2 10" speakers
Chassis
Cabinet
And I have all the stuff I need for the preamp.

Thanks, this looks like a great forum!

[J M Fahey]

Hi Svstee.
*Very* short response (I´m very tired now.after a long day´s work):
1)It won´t work
Besides:
2)Are 30W (which you're *not* getting now) enough for a Jazz Band ?, considering that for Jazz you usually can´t go beyond 50% of your clean power on grounds of dynamic range.
3)ROG, GGG, etc. are very poor "design" references, with some isolated exceptions. You´re better off copying known good commercial equipment. The ESP project (search its topic) is a better alternative. Poor distortion , good Fenderish cleans, you can supply your own 2x15W TDA2030, or even excellent 2x30W TDA2050 with an adequate power supply, which is almost in the JC77 league. .
The one posted is "pedal size" and will explode driving power amps. Good luck.

[J M Fahey]

Hi Svstee. As an example of a good, sound, working chipamp, download >>>http://tremolo.elektroda.net/Firmowe/LANEY/HCM30R.pdf<<< which is a Laney´s 30 W amp, and copy the power amplifier and power supply, which are practically the same as the datasheet suggestion . A 15+15 (or 16+16) V.A.C. , 2 Ampere transformer (or 60 V.A.) transformer will do for a mono 30 W amp; twice as much current (4 A) or VA (120) will do for a very loud sounding 2x30W. You can use ESP´s project 27 preamp with it . Use good speakers. Jensen´s MOD are good and cheap, or search for an equivalent Eminence. Good luck.

[phatt]

Well, I need an amp for my college jazz band. I always wanted a Roland JC, even before I played much jazz I thought they had the best clean tone ever. I have an idea vaguely sort of similar to the JC, two totally separate amps each running into a separate speaker, each voiced a little differently for a nice stereo effect. I came across this
http://eu.st.com/stonline/products/literature/ds/1459/tda2030a.pdf
and my tentative plan is to build two poweramp sections with these, using something like this
http://www.runoffgroove.com/tonemender.html
for each of the two preamps.

Thanks, this looks like a great forum!

Hi svstee,
              Unless I'm mistaken,,,
the Roland Jazz Chorus Amplifier circuit is ONLY stereo when the Chorus is engaged,,no chorus engaged = no stereo,, straight mono or but both poweramps delivering the same sound through two speakers.

The first true stereo chorus in an amp was the selling point of those amps.
A mate I knew had JC120 and it made his all white tripple humbucker LesPaul sound like a tin can.
IMHO the most overrated SState Amp of all time,,,but hey that's kool if you like em.

I know this is slightly of topic but
The HCR30 Laney mentioned here by Fahey is quite a good little Amp just needs a better tone control,, but as you are after a jazz tone then a different preamp/tone section is probably needed.
If you are even remotely thinking of tinkering with different circuits get yourself a breadboard and experiment until you find what you are after.
Otherwise you will waste a lot of time building stuff that ends up in the bottom draw as spare parts.. Just ask me I have lots of those,,,
"Seemed like a good idea at the time trashed boards"
Have fun with it,,it's very addictive.
Phil.

[svstee]

The one posted is "pedal size" and will explode driving power amps. Good luck.

I assume you are talking about the bipolar power supply, correct?
I looked at the HCR30 Laney, but it seems a bit over my head. I all I need is a power supply, can't I fine one isolated?

2)Are 30W (which you're *not* getting now) enough for a Jazz Band ?, considering that for Jazz you usually can´t go beyond 50% of your clean power on grounds of dynamic range.

I think it will be plenty. when I first started playing with them I was using a Fender Frontman 15 with an 8" speaker, and it was almost loud enough.

Thanks for all the help guys!

[J M Fahey]

Hi Svstee and Phatt. What I suggested was to have a look and copy *only* the power amp and power supply; not the preamp and reverb which are slightly complicated for a homebuilder, and, I agree, not that good sounding (although it´s not cr*p either, by any means).
If the little Fender,1 x TDA2030,15 W, with one 8" was "almost" enough, a TDA2050, 30W, and one 10" will probably be enough. Two of them with two 10" or an LM3886 with a good 12" guitar speaker (or 2x10") will be even better, if affordable. With those +-15V from the supply, power a P27 preamp, which so far is the best combination of cost/performance/easy-to-build/easily-available clean preamp I know; if somebody can suggest another, they´re welcome.
It´s as easy as the tonemender, which is a poor design; the power amp suggested is practically the same as the application , with only a couple minor modifications to make it more "guitaristic", but for clean Jazz you can build the "official version" if you wish, and the power supply is simpler (and beefier) than the pedal-oriented one.
There´s a couple of us who will post one of these days a veroboard layout for the P27 preamp; the one for the TDA2030/2050 is already one of the designs included in "Layout creator" and the power supply, well, is up to you.
Bye and good luck.

[svstee]

My goal is a stereo amp, though. Two pre amps into two power amps into two speakers.  I figure I can cheat a bit and have the power amps use the same power supply, but having two separate amps going simultaneously is the #1 goal (#2 is economy).

[J M Fahey]

OK, Svstee, that´s a nice project. If you have any doubt, just ask. 2xTDA2030 will be 30 W total into 2 x 4 ohm speakers, and easily powered by one supply, preferably with 2 x 4700x25; 4x 1N5404 or a 4 amp bridge and a 12+12V, 2,5 or 3A transformer . Good luck.

[svstee]

preferably with 2 x 4700x25; 4x 1N5404 or a 4 amp bridge and a 12+12V, 2,5 or 3A transformer . Good luck.

Forgive my newbhood, but I did not get any of that.
If I understand you up to this point, this
http://www.generalguitargadgets.com/pdf/ggg_bipolar_ps.pdf
does NOT have the power to handle a chip amp, and I need a new power supply. Is there any way you can point me to a solid schematic for one that would work for me?

Will this work for the amp section though?
http://www.generalguitargadgets.com/pdf/ggg_20x0_amp.pdf

[J M Fahey]

OK, now I get you. No problem.
Let´s go step by step.
The GGG TDA power amp´s schematic is right.
The PCBoard looks right but let me re-check it awake.
A couple of questions:
1) Can you (or a friend) make the PCB as posted or you´ll use Vero or perfboard?
2)Can you make some kind of usable chassis for it? (It involves some mechanical skills and access to a couple tools)
3)Can you wire safely the power supply? (It involves working around deadly power line voltages)
Homemaking amplifiers can often be somewhat too much because  of "non-electronic" issues.
Homemakings pedals and such can be more rewarding because they can be Battery (or wall-wart) powered, can be used even without an enclosure or using humble plastic and even cardboard cases and their lower cost/complexity allows throwing them away if necessary.
The suggestion that was posted earlier about getting a "garage sale special" , even if nonworking , but at least to get an enclosure and chassis, maybe even a power supply and suitable speaker, is not bad at all.
Bye.

[svstee]

I have access to all the tools and (free!) material I need for making the chassis and I am comfortable working with mains voltage for the power supply.
I plan on building the GGG TDA on either Perf or Vero, currently undecided. when I do I'll post a layout her for verification.
I would normaly go the route of "garage sale special" but the unique reqrirement for this amp in terms of size make that difficult. I have access to almost unlimited free plywood and THICK steel stud, so materiel for the cab and chassis will not be a factor. I know how to work with it as well.

Thanks for all the help!

[svstee]

I was looking at this again
http://www.generalguitargadgets.com/pdf/ggg_20x0_amp.pdf
and just now saw that it is designed for 9v. I was planning on running it at 18, should I? And if so, what changes do I need to make?

Also, suggestions for a bipolar power supply schematic to use? There is a lot of stuff out there to choose from.