Never done this before: Guitar Amp! - Page 2

Geek · 5th August 2009, 10:12 PM

Quote:

Originally posted by rongon
I prefer the Baxandall(sp?)-style Ampeg tone stack. Meatier, more mids. Smoother overall, but I'm a jazz player, so I would prefer that...

My favorite tone control trick is the tweed-era Fender "Presence" control in the feedback loop of the output stage. As a matter of fact, I was thinking that a simple Tone control (rolloff the highs) coupled with a Presence control would be all that is really needed.

Psssst..... try a parametric mid EQ I designed for CK Amps

http://www.ckamps.com/ToneGeeks/Tone....msg166#msg166

amptramp · 6th August 2009, 01:53 AM

Of course, once you finish the amplifier, you can start immediately on the effects boxes. You can find designs at:

http://www.diystompboxes.com/pedals/schematics.html

and there are others available with pre-etched circuit boards at:

http://www.tonepad.com/

I have a couple of old PA amplifiers that I am converting to guitar duty. I had to travel about 100 miles to get them which is how I came up with my screen name.

Wavebourn · 6th August 2009, 02:08 AM

Quote:

Originally posted by Geek

Psssst..... try a parametric mid EQ I designed for CK Amps

http://www.ckamps.com/ToneGeeks/Tone....msg166#msg166

I like it, very creative!

rongon · 6th August 2009, 02:29 AM

^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
Me too!

chrish · 6th August 2009, 06:35 AM

Thanks for the comments,

I am having fun building this. I hear the comments about MDF vs ply, but unfortunately, I have already completed most of the construction of the cabinet. I don't feel like re-building it at this stage, as progress is slow based on the every second weekend requirement to do it with my son. Perhaps an ooption might be to 'upgrade the cabinet' with him as a future project.

At this stage we have decided against a tolex covering, opting to go for a painted dark charcoal grey hamertone finish. Driver will be covered by a black metal mesh grille. Have mixed the colours of the chicken head knobs up for interest. Gain - blue, tone - red, presence - white, volume - black. Have some chromed corner protectors, so I hope we get a 'retro cool' look.

I am not sure if it is a 'Marshal' or a 'Fender' sound. I will paste the links below to the schematics I used.

I am guessing about two hours of wiring up will have it to the point where we can plug his guitar in to test.

AX84 lead preamp

AX84 20W PP poweramp

Geek · 6th August 2009, 10:00 AM

Thanks on the EQ comments, guys!

Quote:

Originally posted by chrish

At this stage we have decided against a tolex covering, opting to go for a painted dark charcoal grey hamertone finish. Driver will be covered by a black metal mesh grille. Have mixed the colours of the chicken head knobs up for interest. Gain - blue, tone - red, presence - white, volume - black. Have some chromed corner protectors, so I hope we get a 'retro cool' look.

That sounds great!

I hope you post pics.

Quote:

Originally posted by chrish
I am not sure if it is a 'Marshal' or a 'Fender' sound. I will paste the links below to the schematics I used.

I am guessing about two hours of wiring up will have it to the point where we can plug his guitar in to test.

AX84 lead preamp

AX84 20W PP poweramp

My guess is it'll sound Marshall... too much gain in the pre for a Fender sound.

Cheers!

Rob11966 · 6th August 2009, 01:19 PM

Hi Chris,

You mentioned a while ago that you were building this.

It looks great. Another fantastic job.

Where did you get the chassis?

Look forward to seeing the finished product. Good luck.

Rob

rongon · 6th August 2009, 02:49 PM

Yes, more Marshall than Fender. The 470pF cap and two .022uF caps in the tone stack will give a more Marshall-like slope to the filters. (Fender uses 250pF, .1uF and .047uF in those places.) The cathode-follower is also a Marshall feature, absent in the blackface Fender preamp.

It'll be cool, I know that!

--

darryl_h · 6th August 2009, 04:06 PM

Quote:

Originally posted by chrish

I am not sure if it is a 'Marshal' or a 'Fender' sound.

This particular AX84 preamp has a lot of Marshall 'DNA'. The cascaded preamp stages, with a cathode follower driving the tonestack is similar to a "master-volume" Marshall amplifier. You can compare your circuit to typical Fender and Marshall schematics here:
http://www.schematicheaven.com/fende...luxe_aa763.pdf
http://www.schematicheaven.com/marsh..._50w_2204u.pdf

An Australian discussion board you may find interesting for its local content:
http://www.guitargear.net.au/discussion/index.php
There is an "In The Shed" area of the forum, where guitar amplifier builders can discuss their projects.

chrish · 7th August 2009, 01:21 AM

Thanks for the interest!

Yes, definitely photos to follow with progress. The chassis is just a standard Hammond. I have primed it with an etch prime (straight from a spray can) and then coated with a burnished aluminium spray (from a can also). I labelled with decals, just like those model aeroplane kits you built as a kid

. Decals were made from some decal paper that goes in to your laser printer. It works pretty well. After applying decals I gave a couple of coats of clear. Looks a little nicer than the raw aluminium and does not scratch as easy.

Cheers,

Chris

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
4x12 Guitar cab using guitar and bass speakers help	andrewskaterrr	Instruments and Amps	15	23rd April 2009 11:43 PM
JLH Guitar Amp	lcsegeng	Solid State	1	14th March 2007 07:12 AM
DIY guitar	BassAwdyO	Instruments and Amps	41	8th January 2006 06:32 PM
Guitar to DIY amp?	silentblackhat	Instruments and Amps	2	27th July 2004 06:36 PM
6V6 Guitar Amp	SHiFTY	Tubes / Valves	2	5th August 2003 02:10 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

6th August 2009, 01:53 AM	#12
amptramp diyAudio Member Join Date: Jul 2009	Of course, once you finish the amplifier, you can start immediately on the effects boxes. You can find designs at: http://www.diystompboxes.com/pedals/schematics.html and there are others available with pre-etched circuit boards at: http://www.tonepad.com/ I have a couple of old PA amplifiers that I am converting to guitar duty. I had to travel about 100 miles to get them which is how I came up with my screen name.

6th August 2009, 02:29 AM	#14
rongon diyAudio Member Join Date: Jul 2009 Location: Across the river from Rip's big old tree...	^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ Me too!

6th August 2009, 06:35 AM	#15
chrish diyAudio Member Join Date: Oct 2003 Location: Sydney	Thanks for the comments, I am having fun building this. I hear the comments about MDF vs ply, but unfortunately, I have already completed most of the construction of the cabinet. I don't feel like re-building it at this stage, as progress is slow based on the every second weekend requirement to do it with my son. Perhaps an ooption might be to 'upgrade the cabinet' with him as a future project. At this stage we have decided against a tolex covering, opting to go for a painted dark charcoal grey hamertone finish. Driver will be covered by a black metal mesh grille. Have mixed the colours of the chicken head knobs up for interest. Gain - blue, tone - red, presence - white, volume - black. Have some chromed corner protectors, so I hope we get a 'retro cool' look. I am not sure if it is a 'Marshal' or a 'Fender' sound. I will paste the links below to the schematics I used. I am guessing about two hours of wiring up will have it to the point where we can plug his guitar in to test. AX84 lead preamp AX84 20W PP poweramp

6th August 2009, 01:19 PM	#17
Rob11966 diyAudio Member Join Date: Jun 2007 Location: Australia	Hi Chris, You mentioned a while ago that you were building this. It looks great. Another fantastic job. Where did you get the chassis? Look forward to seeing the finished product. Good luck. Rob

6th August 2009, 02:49 PM	#18
rongon diyAudio Member Join Date: Jul 2009 Location: Across the river from Rip's big old tree...	Yes, more Marshall than Fender. The 470pF cap and two .022uF caps in the tone stack will give a more Marshall-like slope to the filters. (Fender uses 250pF, .1uF and .047uF in those places.) The cathode-follower is also a Marshall feature, absent in the blackface Fender preamp. It'll be cool, I know that! --

7th August 2009, 01:21 AM	#20
chrish diyAudio Member Join Date: Oct 2003 Location: Sydney	Thanks for the interest! Yes, definitely photos to follow with progress. The chassis is just a standard Hammond. I have primed it with an etch prime (straight from a spray can) and then coated with a burnished aluminium spray (from a can also). I labelled with decals, just like those model aeroplane kits you built as a kid . Decals were made from some decal paper that goes in to your laser printer. It works pretty well. After applying decals I gave a couple of coats of clear. Looks a little nicer than the raw aluminium and does not scratch as easy. Cheers, Chris