Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Erik Aa on May 14, 2022, 01:52:36 pm

Title: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Erik Aa on May 14, 2022, 01:52:36 pm: Hi all.
I recently got an Ashdown fallen angel fa60 dsp amp dirt cheap. It is a 50 watt head with 2 el34 and 12ax7s in the preamp section.

I am thinking about gutting it and rebuild it, take some of the usable parts and build a point to point 50 watt bass amp head.

One candidate is the jmp 1986. But I am open to any and all suggestions. The 1986 has a choke, and there is no choke in the ashdown.

What do you think and suggest? Thanks!

Erik
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Latole on May 14, 2022, 02:55:22 pm: Bought a choke.

Schematic here;

Ashdown:

https://el34world.com/charts/Schematics/files/Ashdown/Ashdown_fallen_angel_60_schem.pdf

Marshall Bass 1986;

https://el34world.com/charts/Schematics/files/Marshall/Marshall_jmp_bass_50w_1986.pdf

or ;
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Latole on May 14, 2022, 02:57:48 pm: Clone ;

https://www.thegearpage.net/board/index.php?media/f8e2faf4-3ff4-4ffd-a557-97993810b0c8-jpeg.243158/
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: kagliostro on May 14, 2022, 03:12:20 pm: https://www.thallenbeck.com/blog/posts/d-i-y-ampeg-b15n-fliptop-clone/ (https://www.thallenbeck.com/blog/posts/d-i-y-ampeg-b15n-fliptop-clone/)

Ciao

Franco
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Erik Aa on May 14, 2022, 03:29:27 pm: Thanks for inspiring suggestions. Any suggestions for an amp/schematic without a choke?
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: sluckey on May 14, 2022, 03:54:09 pm: Quote from: Erik Aa on May 14, 2022, 03:29:27 pm
Thanks for inspiring suggestions. Any suggestions for an amp/schematic without a choke?
Ampeg, Supro, Traynor, Trainwreck all have amps with no choke. Plenty more too. Just browse through the schematics in the Tube Amps Schematic Library. Link at the bottom of this page.
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: kagliostro on May 14, 2022, 04:43:32 pm: Quote
Any suggestions for an amp/schematic without a choke?

http://ctgelectronics.weebly.com/custom-amplifier---fcn-51-b.html (http://ctgelectronics.weebly.com/custom-amplifier---fcn-51-b.html)

--

If you want you can build your own "choke"

(https://i.imgur.com/2aYteJP.png)

https://www.loetstelle.net/projekte/gyrator/gyrator.html (https://www.loetstelle.net/projekte/gyrator/gyrator.html)

(https://www.loetstelle.net/content/projekte/gyrator/images/brdhi.gif)

Franco
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: PRR on May 14, 2022, 05:17:14 pm: Quote from: Latole on May 14, 2022, 02:55:22 pm
Schematic here;
Ashdown:
https://el34world.com/charts/Schematics/files/Ashdown/Ashdown_fallen_angel_60_schem.pdf

Hmmm... that "Fallen Angel 60W" PDF's second page is for a "20/40 HM Guitar Amp". Meaning it may not be right for a 60W?

I don't think there is any reason not to use the stock (or repaired) FA 60W power supply, with the 470r in place of a choke. But if you really need to carry (and buy/ship) another pound of iron, put a choke in.
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Latole on May 15, 2022, 03:04:10 am: Traynor YBA-4 . YBA-1 Bass Master

https://el34world.com/charts/Schematics/files/Traynor/Traynor_yba_4.pdf
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Latole on May 15, 2022, 03:11:50 am: Choke are cheap ; $25
https://www.tubesandmore.com/products/transformers_chokes?filters=969a846c65a969

Heyboer ; $34 ;https://shop.amppartsdirect.com/products/marshall-vintage-plexi-style-3-hy-choke-apd-8058h-by-heyboer
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Erik Aa on May 15, 2022, 01:19:47 pm: Thanks a lot. I have been thinking about going the Traynor route. Some of them run crazy high plate voltage though. Do they eat tubes or is this issue exaggerated?
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Latole on May 15, 2022, 01:30:44 pm: Some Traynor schematic I saw with EL34 / 6CA7 use 433 volts DC
Title: Re: Gutting Ashdown guitar amp and rebuild as point to point bass amp
Post by: Latole on May 16, 2022, 03:48:53 am: If I want a "Marshall" tone I won't built à Traynor, I'll spend $25 + shipping for a choke