New amp project

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Kalle
Posts: 180
Joined: Sat Apr 03, 2010 7:22 pm

New amp project

Post by Kalle »

Hi Guys
As you might remember is that I have a Ibanez Valbee combo 5W tube amp (that has been heavily modified internally).
In original it has a small cabinet with 6.5" speaker. But a with 12" speaker it sounds much better.
I had a 12" inch Bugera speaker laying around and an idea started to spread in my head.
Why not build a 12" speaker combo cabinet for the Valbee amp.
And here is the result :
Image
Image
Image

The cabinet sides are made of 20mm thick pinewood, front and back of 10mm fiberboard and its covered with vinyl false leather.

Kalle
Last edited by Kalle on Sun Dec 14, 2014 3:26 pm, edited 1 time in total.
Tanglewood TW28STE (Shadow P7 EQ system) steelstring Dreadnought
Yamaha RBX 270 bass guitar with Laney DB150 amp.
Yamaha RGX 320 electric guitar with Egnator Tweaker tube amp.
http://www.soundclick.com/kalleinsweden
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Golfxzq
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Joined: Sun Apr 04, 2010 3:13 am

Re: New amp project

Post by Golfxzq »

Very nice work!! I would love to see some pictures of the inside and maybe a sound clip? Did you have any problems matching the ohm resistance?
"Whether you think that you can, or that you can't, you are usually right."
- Henry Ford
MichaelRobinson
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Joined: Mon Oct 03, 2011 10:20 pm

Re: New amp project

Post by MichaelRobinson »

Yes. "fun" thing to do, I supose.
With youre know how it's no wonder that you know what you do.

Hope you upload a sound clip, if you have a mic.

Take care
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HalfBlindLefty
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Re: New amp project

Post by HalfBlindLefty »

Looks great Kalle, good job !
Not to the Demo sounds I'm missing here :)
A long time ago, in the old forum : Registered: Mon, 27 Nov 2006. Wonder were the other old members all went....
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Kalle
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Re: New amp project

Post by Kalle »

Golfxzq wrote:Very nice work!! I would love to see some pictures of the inside and maybe a sound clip? Did you have any problems matching the ohm resistance?
The inside of the cabinet is painted black.
Matter of fact, i needed to install reinforcements in the top of the cabinet ( around the amp ) to reduce vibrations from the speaker going to the amp (tubes).
The original speaker was a 4 ohm, but the amp seems to like 8 ohm, as I have used a 8 ohm speaker in this amp for long.

Kalle
Tanglewood TW28STE (Shadow P7 EQ system) steelstring Dreadnought
Yamaha RBX 270 bass guitar with Laney DB150 amp.
Yamaha RGX 320 electric guitar with Egnator Tweaker tube amp.
http://www.soundclick.com/kalleinsweden
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Kalle
Posts: 180
Joined: Sat Apr 03, 2010 7:22 pm

Re: New amp project

Post by Kalle »

HalfBlindLefty wrote:Looks great Kalle, good job !
Not to the Demo sounds I'm missing here :)
Hi , I might do some recordings as got myself a second hand Zoom H4 (handy recorder).
The Valbee is a 2 tube amp ( one 12AX7 preamp tube and one 6L6 power tube in single ended Class A )
You can see the block diagram here
Image
I have totally changed the "Boost" preamp part in the amp from the original "diod distorsion" to true tube distorsion.

/Kalle
Tanglewood TW28STE (Shadow P7 EQ system) steelstring Dreadnought
Yamaha RBX 270 bass guitar with Laney DB150 amp.
Yamaha RGX 320 electric guitar with Egnator Tweaker tube amp.
http://www.soundclick.com/kalleinsweden
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Kalle
Posts: 180
Joined: Sat Apr 03, 2010 7:22 pm

Re: New amp project

Post by Kalle »

Here are som sound samples:
Clean rythm guitar Stormy Monday (ala T-Bone Walker)
https://app.box.com/s/4fir1a9q1pq33epj6nz2
Distorted rythm guitar Layla (Cream)
https://app.box.com/s/682ti46lmabgrzja1tzh

Its my Yamaha electric guitar in both recordings and same amp settings, just pressed the "boost" button for distortion
Kalle
Tanglewood TW28STE (Shadow P7 EQ system) steelstring Dreadnought
Yamaha RBX 270 bass guitar with Laney DB150 amp.
Yamaha RGX 320 electric guitar with Egnator Tweaker tube amp.
http://www.soundclick.com/kalleinsweden
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Golfxzq
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Joined: Sun Apr 04, 2010 3:13 am

Re: New amp project

Post by Golfxzq »

Cool... great sound. Those little Zoom recorders are amazing, they pick up every little detail with hardly any background interference. The amp sounds super, you have done well.
"Whether you think that you can, or that you can't, you are usually right."
- Henry Ford
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12bar
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Re: New amp project

Post by 12bar »

Kalle wrote:Its my Yamaha electric guitar in both recordings and same amp settings, just pressed the "boost" button for distortion
A big difference for a small button! As already said, well done! :thumbsup:
MichaelRobinson
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Joined: Mon Oct 03, 2011 10:20 pm

Re: New amp project

Post by MichaelRobinson »

Sounds good with that distortion. Fantastic litle thing you have modefied to suit youre needs. It's for youre needs, I guess ? The thing rocks....... :music2: :banana:
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vancouverois
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Joined: Tue Apr 06, 2010 5:55 pm

Re: New amp project

Post by vancouverois »

Nice job Kalle, it looks and sounds great!
Kalle wrote: I have totally changed the "Boost" preamp part in the amp from the original "diod distorsion" to true tube distorsion.
Did you add the tube and keep the diodes or did you definitively suppress the diodes ?
Jan 15th 2007
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Kalle
Posts: 180
Joined: Sat Apr 03, 2010 7:22 pm

Re: New amp project

Post by Kalle »

Hi
Here comes the technical stuff..
The first thing I did was to cut the diodes, that made a significant improvement.
Next step was to convert the boost stage from a cathode follower stage (driving the diodes) to a normal "overdriven" Triode gain stage.
The same time I added a potentiometer after the Triode gain stage, givin me a "post gain volume control".
This make it possible to have the same volume in Clean and in Boost(distorted) "channel" .
Then I modified the Power Amplifier with a bias current control potentiometer.

This has been my modify and learning project..

Kalle
Tanglewood TW28STE (Shadow P7 EQ system) steelstring Dreadnought
Yamaha RBX 270 bass guitar with Laney DB150 amp.
Yamaha RGX 320 electric guitar with Egnator Tweaker tube amp.
http://www.soundclick.com/kalleinsweden
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Kalle
Posts: 180
Joined: Sat Apr 03, 2010 7:22 pm

Re: New amp project

Post by Kalle »

Golfxzq wrote:Very nice work!! I would love to see some pictures of the inside and maybe a sound clip? Did you have any problems matching the ohm resistance?
Hi
I have updated the first post with better pictures including a picture of the inside
/Kalle
Tanglewood TW28STE (Shadow P7 EQ system) steelstring Dreadnought
Yamaha RBX 270 bass guitar with Laney DB150 amp.
Yamaha RGX 320 electric guitar with Egnator Tweaker tube amp.
http://www.soundclick.com/kalleinsweden
Onut
Posts: 1
Joined: Sun Mar 15, 2020 4:19 pm

Re: New amp project

Post by Onut »

Hi,
Can I have a schematic of your mod. I also have a Valbee and I would like to do the same with it.
Thank you!
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12bar
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Joined: Thu Mar 25, 2010 12:05 pm

Re: New amp project

Post by 12bar »

Maybe you should write a PN or visit him on soundclick, the last login is a while ago.
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