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 Building a practice Bass amp, Part Two
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 Return to top of page · Post #: 1 · Written at 8:37:39 AM on 13 June 2019.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 917

Hullo all, I have progressed this project to the point where the cabinets are made in rough wood, the chassis is fitted and running.
There was some excitement in choosing a suitable speaker to suit the ported cabinet.
The first driver I tried was just rubbish.
The one good thing about making a device that does not work very well; the moves that you do to make it work better provide lessons you would never learn if all went well from the start!

I have made hundreds of guitar amps over the years and am still learning.
When you read about this amp you will wonder why I am using 1970's techniques and valves just to get 30 watts.
It has been pointed out I could be using a modern amp module that gives at least 1000 watts from a something the size of a matchbox, has 110% efficiency (so I am led to believe) and a modern Asian speaker that can be fitted to a flat board and produce notes from DC to 1MHz.

Well, I'm still also waiting for anti-grav generators to pop up on eBay and the Warp Drive coil to be invented, so for the moment i'll play about with what I know and understand (sort of).

I'll email the usual PDF to Brad and you can share the adventure.

Cheers, Fred.

Design of a practice bass amplifier - Part 2

 Return to top of page · Post #: 2 · Written at 5:58:59 AM on 15 June 2019.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 917

Thanks to Brad for loading in the pdf.

A couple of corrections to the text, I really must have a word to the proof reader but he never listens!

graph 75. text change, "when vented the phase angle is leading capacitive, when closed lagging inductive"

below block of pix 76 to 78, text change "75" should be "78"

Sorry about that folks, i'll do better next time!


 Return to top of page · Post #: 3 · Written at 4:36:34 PM on 16 June 2019.
Brad's avatar
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 6532

No worries, Fred. I apologise for not announcing the upload on Friday night. I did this fairly late and I am not on the ball in the wee hours.

A valve a day keeps the transistor away...

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