The RADIO-TONE

[tubelectron]

Hi All,

Another release, probably one of the most compact standalone combo guitar amplifier ever made ?

The RADIO-TONE :

[img1092]http://img15.hostingpics.net/pics/554867IMG3443.jpg[/img]

[img1187]http://img15.hostingpics.net/pics/329471IMG3447.jpg[/img]

[img:640:480]http://img15.hostingpics.net/pics/445340IMG3239.jpg[/img]

[img:480:640]http://img15.hostingpics.net/pics/135044IMG3235.jpg[/img]

[img:640:480]http://img15.hostingpics.net/pics/946781IMG3230.jpg[/img]

[img:640:480]http://img15.hostingpics.net/pics/771689IMG3232.jpg[/img]

Built from scratch :

[img:640:480]http://img15.hostingpics.net/pics/595153IMG2870.jpg[/img]

[img:800:600]http://img4.hostingpics.net/pics/128271IMG2849.jpg[/img]

Intended to enter a guitar case :

[img:480:640]http://img4.hostingpics.net/pics/676949IMG2862.jpg[/img]

Compared to the size of a Fender Greta :

[img:640:502]http://img4.hostingpics.net/pics/363175IMG3123.jpg[/img]

NOS 60s AlNiCo OAKTRON 5"1/2 loudspeaker :

[img:640:618]http://img15.hostingpics.net/pics/411473oaktron1red.jpg[/img]

[img:640:592]http://img15.hostingpics.net/pics/223660oaktron3red.jpg[/img]

A quick sample with a Squier Std Strat and a touch of EH Cathedral Reverb :

https://soundcloud.com/tubelectron/r05- ... l-bluesmp3

Specs :

- standalone 230/240VAC combo amplifier
- 2W RMS clean sound.
- one tone, one volume.
- ECL86/6GW8.
- 5"1/2 speaker.
- 10mm plywood cab bi-color Tolex, salt-and-pepper grillcloth.
- dimensions = 200x150x80mm
- mass = 2kg

A+!

[Reeltarded]

OMG!! Can you fold fitted sheets?

BURN THE WITCH!!

Very cool!

[tubelectron]

OMG!! Can you fold fitted sheets?

BURN THE WITCH!!

Very cool!

Thanks Reeltarded,

Burn the witch

Yes, the chassis needed to be fold and cut to exact dimensions of the cab. Since it is made of 1.5mm aluminum and small, it was possible to bend, cut and shape easily in a vice.

The chassis is flat-screwed in the cab and can be removed without effort nor disconnecting, in order to ease servicing and modifications. This is the same for the speaker, which supports its output transformer.

Quick sound comparison between the Fender Greta and the RADIO-TONE. In each sample, the Greta plays in first, the RADIO-TONE in second. The guitar is a Fender Telecaster :

https://soundcloud.com/tubelectron/r05- ... e-cleanmp3

https://soundcloud.com/tubelectron/r05- ... erdrivemp3

A+!

[xtian]

Formidable!

The build is a beauty.

The sound samples are ... did you cheat? The Greata sounds like poop, and your amp sounds awesome! I think the microphone was about 40 feet farther away from the Greta...

[tubelectron]

Formidable!

The build is a beauty.

The sound samples are ... did you cheat? The Greata sounds like poop, and your amp sounds awesome! I think the microphone was about 40 feet farther away from the Greta...

Thanks again xtian,

The 10th picture posted above represents the real situation where I made the Greta vs. RADIO-TONE sound samples, along with my Roland R-05 recorder. You can see that the distances are the same.

At that time, the chassis of the RADIO-TONE was not already installed in the cab, so that's why you can have a doubt about the sample's validity, but this is not a joke, it's reality.

I borrowed the Greta at my local music shop for that test, and yes, I have been amazed (or deceived) by the poor performance both in tone and power of the Greta, nearly 3 times bigger than the RADIO-TONE...

The Greta's speaker is a 4" trebly and unefficient model, mounted in a closed cab. Its 12AT7 output tube (both sections //) is barely able to reach 0.5W RMS clean on a 8ohms load. Here are the differences...

I wonder if the Greta is a great commercial success . At first, I was thinking about building one, but hearing the results, it's not worth !

A+!

[Ron Worley]

Vous ette un artist magnifique! Pardon mon mauvais Francais...

[xtian]

Well, sounds really good. Is this amp just two triodes in total?

[tubelectron]

Vous ette un artist magnifique! Pardon mon mauvais Francais...

Merci Ron ! Votre Français n'en est pas moins tout à fait compréhensible...

Well, sounds really good. Is this amp just two triodes in total?

My RADIO-TONE uses a triode-pentode ECL86/6GW8.

The Fender Greta uses 3 stages : 2 successive preamp stages from a 12AX7 and a final stage consisting in a // 12AT7.

A+!

[martin manning]

Looks and sounds great! Would you willing to share the schematic?

[tubelectron]

Looks and sounds great! Would you willing to share the schematic?

Thanks martin,

The RADIO-TONE schematic is inspired by the 60s Magnatone 411 circuit, with a few differences and no tremolo circuit. Here it is :

[img811]http://img11.hostingpics.net/pics/30886 ... 052015.jpg[/img]

A+!

[martin manning]

Fantastic, thanks!

[Teleguy61]

Lovely work.
Thanks for sharing pics and info.

[tubelectron]

Thank you, guys !

A+!

[M Fowler]

Nice job building these sweet little amps.

[tubelectron]

Thanks M Fowler,

A+!