5 watter

Karel-Mars

Hi Ampheads

I have been wanting to build a 5 watter for a while, and when I found a seemingly appropriate power transformer, it was time to get the soldering iron out.

I had a cabinet I made a while ago. I was curious how 8 inch MOD sounded like , so in it went!

I had a chassis bent and planned a layout. Drilling was next.

Drilling finished! Most hardware mounted. It is starting to look like an amp.

The action now moves inside...

The filament wires are in place, as well as the cathode resistor

I decided to go with paper oil caps for a brown sound.

Time to power up and hear the beast roar

It sounds good... no hum and silent when cranked.

CDee

Good job... Looks really good...
What would be the tonal differences between the 8" and a 10" speaker?

MikeM

What circut is it? Looks awesome i'm saving every penny ?

matta

Hey Karel,

Looking good! I had a 6" Mod on my Fender Champ, pretty nice speakers (looking forward to my C12N's for the 2 x 12 as well!).

What is the circuit based on? Looking a little like the Hoffman Schedule 40, which if I'm not mistaken is based on the Gibson GA5, but with an EL84 on the output in place of the original 6V6?

Those 470uF/200V filter caps look pretty beefy ?

Cheers

Matt

aja

Karel, fantastic work man, looks great!

matta wrote Hey Karel,

Looking good! I had a 6" Mod on my Fender Champ, pretty nice speakers (looking forward to my C12N's for the 2 x 12 as well!).

What is the circuit based on? Looking a little like the Hoffman Schedule 40, which if I'm not mistaken is based on the Gibson GA5, but with an EL84 on the output in place of the original 6V6?

Those 470uF/200V filter caps look pretty beefy ?

Cheers

Matt

You know, I still laugh at how many people can't believe the tone of the little fender champ you rebuilt! ?

FatBoy

Cool, are you going to post some sound clips?

Karel-Mars

Let's see if the schematic loads

aja

Interesting, like a stripped down version of this:

http://akavalve.blogspot.com/2008/12/fender-champ-comparing-5f1-and-5e1.html

MikeM

Wow really simple schematic ?

I'm "AMPed" for clips hahaha ?

Karel-Mars

CDee wrote What would be the tonal differences between the 8" and a 10" speaker?

This is a tough question :-\ I think the 8inch has more punch and the 10inch more bass. This all depends on cabinet dimensions and assuming the 8 and the 10 has the same specifications, esp SPL.

The 8 inch pushes a smaller column of air than the 10 inch, so the power amp has more energy available to shake it. So the 8 inch should be louder.

The test here was if the 8 inch would have enough bass. I am happy - the lower E-string is as loud as the rest.

Heath

so how easily can the power , output transformers be found , and how easily can the choke be found ....... cos i want one .. ?

JohnnyReggae

As a matter of interest..... what did it cost to put it together ? Vaguely interested in doing a project similar to this myself, costs depending of course ?

JoeyBones

That looks way too simple. What's the catch ???

aja

Karel Mars wrote
The 8 inch pushes a smaller column of air than the 10 inch, so the power amp has more energy available to shake it. So the 8 inch should be louder.

I thought more air being moved means more volume? ???

Gearhead

Karel Mars wrote
CDee wrote What would be the tonal differences between the 8" and a 10" speaker?
{...} So the 8 inch should be louder

Karel my guru I am afraid this is very little information regarding the differences. The MOD 10" is actually higher efficiency than the 8".

@CDee: The efficiency of speakers tends to vary a lot so one had better look up the SPL. This is given in dB at one metre from the speaker mounted on an infinite baffle at a signal of 2.83V and averaged over the frequency range of the driver, so it makes sense to have a look at the frequency response diagram (you don't need 20-200Hz in a guitar speaker). It also makes sense to look at the impedance at the same time, because a 4ohm speaker puts out 2x more power at that same 2.83V.

@CDee: To try to answer the original question about the 8 or 10 inch: The other factor would be why you want a 5 Watt tube amp: to play it at 6 Watt ? so all the tone with none of the tinnitus. If this is not the reason go buy/build a 15W to be able to play small gigs in a band and never worry about being loud enough. If you can be happy with the volume of 5Watt multiplied by the SPL of the speaker of choice you're good to go (BTW this will also be enough for most band practice requirements). Moreover, since (more than) half the tone of your combo is in the speaker, you'd better research it a bit more than just looking at SPL. Remember that we are used to hearing 12" speaker setups on records, like Jensens and Celestions.

matta

Karel, did you try your design with an octal tube as well? What made you go with the EL84 over say a 6V6?

Cheers

Matt

MikeM

CDee wrote What would be the tonal differences between the 8" and a 10" speaker?

Lets play nice.

Manfred-Klose

While we are on the topic of speakers, here is site i found that explains how speakers work in a language that guitar players understand, Plus the pictures makes it so much easier to understand ?

There is about 14 speaker related topics:

http://electronics.howstuffworks.com/speaker6.htm

enjoy!

Gearhead

Methinks everyone should have at least one of these amps ?
At least everyone from Gauteng so we can have a Joburg tube amp workshop again soon ?

@ Matta: :goodtimes:

matta

Gearhead wrote I can't begin to describe how sorry I am for not making it clear I was trying to answer CDee's question. I have edited my post to better reflect that. Karel might explain to you how I asked him to put up this thread about his 5 Watter in the first place, which will also explain my frustration with the fact that you don't send me a pm first. You're the moderator, you could even have deleted it; I cannot anymore.

Gearhead,

I removed my comments, your post just read very condescendingly and I thought it was a tad out of place. RE being a moderator, I ONLY moderate the Effects forum and have no mod/edit privileges outside of that forum, other than my own posts.

Cheers

Matt