HTH AMPLIFICATION, 10w class A EL34 combo

This was a solid stage Marshall combo from the mid 80s that was gutted and rebuilt into a single ended, class A amp using an EL34.

The amp has a 'valve select' feature on the back panel to accept 6V6, 6L6, EL34 or KT88 valves (tubes to you American folks). It'll basically take any octal (8-pin) output valve by using one of the four 'bias' settings.

The video quality is pretty crap - I shot this on my digital camera using the video funtion. The sound is 'ok' surprisingly, but the camera is very hissy (the amp doesn't sound hissy like that in person). Needless to say, it's much nicer sounding in person.

These were just a couple of riffs off the cuff (hence the mistakes) using the guitar's volume to control the gain. When you hear the second section with the EVH riff, thats the high gain setting (the first AC/DC stuff is using the low gain setting). Both modes are footswitchable, oh, and there's a valve-driven effects loop on the back.

The speaker is an old Celestion G12M-70 which really works well in this amp despite the poor reputation they have. The preamp valves are EH 12AX7s and the output valve a NOS Siemens EL34.

The guitar was a 1990 Les Paul standard loaded with a Bare Knuckle Pickups Abraxas set.

Category:

Music

Tags:

• Marshall
• EL34
• class A
• valve
• tube
• EVH
• HTH
• SE
• single ended
• 6L6
• 6V6
• KT88
• 6550
• KT77
• 6CA7
• 10w
• Bare Knuckle Pickups
• BKP

[innuendo9999]

hi, do you have the schematic and the layout? great job, i like to build it .

[TeleCustom72]

@innuendo9999: Glad you like the amp, however no schematic will be made publicly available - I spent a long time in R&D on this amp. If you want one, PM me to discuss further.

[relicelite]

sound great , i hope you can record with mic in the near futur to show the true potential of your amp ^^

i got a question too , where did you make the faceplate of your amp ? it got an awsome professional look !

[TeleCustom72]

Glad you like the amp - Its with the guy I made it for now (FelineGuitars), so I won't have the opportunity to do better clips. These clips are just supposed to give you an idea of how the amps sound - in person they're a million times better. The faceplates are custom made for me by a local engraving company. Cheers, Ian

[Dreichlift]

Great sounding amp. Just a quick question though, do you have to rebias if you change tubes of the same type or are the 4 bias settings self biasing?

[TeleCustom72]

The output stage is cathode biased, so the 4 bias settings are indeed self biasing. You can put any EL34 in the amp and it'll be fine. There is no marking on the amp for KT66s, but as they bias the same as 6V6s, you can use the 6V6 setting. Same with 6CA7s - they bias up like EL34s).

[innuendo9999]

Hi, do you have a schematic and a layout?

i like it and like build too.

[ACDCarchives]

Hell Ain't A Bad Place To Be my friend!

[TeleCustom72]

Cheers, I appreciate the comment. Going to record a few more clips with other valves in the output stage, maybe set the amp for more of a Fender tone with some reverb in the effects loop

[psymetal]

sounds great HTH :)