The Hundred-Buck Amp Challenge

I may be wrong, but it seems I can discern some kind of stereo effect which is not possible with a single microphone. Like I said, I may be wrong.

Really nice little jam though. Very tasty, and a really great tone regardless.


It might be that you are hearing a minor channel shift.

You record the track, then you duplicate the track and shift it a couple ms.
It adds a bit of fullness and a kind of delay effect type sound.
Very easy to do in cubase or even cakewalk.
 
It might be that you are hearing a minor channel shift.

You record the track, then you duplicate the track and shift it a couple ms.
It adds a bit of fullness and a kind of delay effect type sound.
Very easy to do in cubase or even cakewalk.

Boss has a line of stereo effects pedals. I was just going to try out my Boss RV5 in stereo. I plug in one guitar and then two amps.

What you describe could be a stereo chorus pedal. Yes they make those too.

One can also use two mics at different distances to the speaker and get about a millisecond of delay per foot of separation.

I hope it turns out I don't like stereo, doubles the cost
 
costis_n, if you figure that you get half the tube gain in the circuit you still have 1200 before the tone stack, and 30 after it to drive the GU-50.

80mA and 500V puts you at -27.5 V bias, so you need 55Vp-p drive to the grid.

Figure your gain as EF80 - 40, ECC81 - 30, Tonetstack - 1/5, ECC81, 30...

I get a 5X loss thoerugh my tonestack (80% loss) and it can vary a great deal depending on the tonestack, but using this value you get 55Vp-p at the GU50 with 15mV input, so I think you will have plenty of gain, and probably enough gain for overdrive.

I'm running 40, 1/5 (tonestack), 25, 25, 2, but I only need 4Vp-p drive.

You may want to move the tonestack after the EF80 and before the first ECC81, but use a high Z tonestack if you do as it will heavily load the pentode output (which may be good for distortion if you want that).

After some though, here is my proposed lineup
ECF80 -> Volume -> bass/treble -> ECF80 (maybe with variable gain) -> ECC81 -> ECC81 -> Master Volume -> GU50

I chose ECF80 because of its high current&relatively low gain. I am also debating whether gain will be excessive, so maybe it's better to operate 2nd section of ECC81 as a cathode follower?

Thoughts?
 
You're a funny guy. Funny guys tend to exaggerate and to make wild assumptions - that's what makes them funny. Not long ago you said that Fender doesn't make a good guitar since 1967 and now this. What is a proper amp? One that does sound good? OK, now we now yours isn't so why bother building it? There it goes your 1st prize. Out of the window. Whatever sound quality I want? Wow, I want you to produce my next record.

Who says editing your music is cheating. I don't remember anyone saying it. If that's cheating then using your awesome sounding guitars is also cheating. How can I compete against you playing a no name telecaster?
Oh man, reading your posts is a lot of fun. Keep them coming.
Not my experience. I have heard great sound live with no effects and no EQ.

Gday Cassiel, my old sparing partner, hahaha!
How ya been buddy?

Yes, I did say Fender hasn't made a good guitar since 1967, not sure what you meant by "& now this"?
I think I get it, yes you can even make reproduction Fenders sound ok with effects or mixing etc.
There were no more real Fenders made after 1967 only copies that used the original name.

Now they are manufactured in china I believe, what a shame, the poor old Fender has been shunted off to whatever country will manufacture them the "cheapest" ever since the business was sold in 1967.

They were originally intended to be used for use in Orchestra's, hence the need for amplification & once Mr Leo Fender realised what everyone was doing with them he got disheartened & sold the business.
Don't think he was into Drugs, Sex & Rock & Roll.

But hey what a business he only had it for a few years & sold it for about $16,000,000.00 in 1967, now that was a lot of money back then.

Hahaha, yes I am a funny guy.
I agree, my little amp has a lot of work needed, it's getting there though & has come a long way since the second test.
It's not really about winning, for me it's about seeing what others can come up with.

Everybody seems to think that guitar amps are simple to make or they are the cheapest worst type of amplifier, to me audio amps are simple to make & guitar amps are harder.
What I mean by that is that for an audio amp you just want a nice clean sound with minimul distortion etc.
But for a guitar amp you need nice distortion & or colouring that is pleasant to the ear, not as easy as some may think & I bet a lot of you are finding that out right now?
Especially when you have only $100 to spend.

What a lot of people forget is that an audio amp has just got to amplify "studio quality sound" from records, CD's etc & not crude sound from guitar pickups.
Not to many audio amps sound good when you plug a guitar into them, otherwise we would be using them?

As you know the way to get high quality sound is by mixing correctly, so yes I can voice most things to suit customers, that's part of what I do actually.
These days it's even possible to make the worst singing voice sound like a good singing voice.

You know what a proper amp is, yes, one that sounds nice in all settings.
Even that is personal opinion though.

Sorry, I didn't know that you can mix your sound clips from the little amps for the challenge?
So you can then?
All I want to do is get the recorded sound the same as the live sound because my mic & computer do change the live sound a lot.
I did think it would be cheating to mix or edit the sound?

Yes, I have to agree, I have heard some ok sound live but not "great sound" without mixing correctly etc, that's what I meant.
Sometimes you think boy that's sounds good only to realise the next time you here it that it wasn't as good as first thought.
Depending on how many drinks or whatever one has had at the time.

AC/DC recently toured down here, even there live sound was not anything to write home about. Then you talk to someone else & they say, they sounded great??

I'm glad you like reading my replies haha, as long as you realise there is no malice or sarcasm intended in any reply.

Australians are known for what we call Sh*t stirring or pulling the P*ss out of each other & sometimes people from other countries don't share the same sense of humour, so chill out man & have another beer on me hahaha!

Cheers
"The Funny Guy"
 
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They may trip over their own egos, but they are both far better guitar players than most of us. I saw them both with Kenny Wayne Shepperd on the original G3 tour about 15 years ago. Didn't convince me to go out and buy either of their CD's, but I did buy some KWS music. Kenny has come cool cars too.

Gday tubelab,

Yeah your right, they are talented guitar players that's for sure, if you like that sort of thing of course.

In America they call it big ego's, in Australia we call it something else.
I'll let the Picture attached explain it all.
It still doesn't take away from there guitar playing though, not to mentioned the endless hours of practice to get there.
There is a lot of hours of practice between those two.

Cheers
"The Funny Guy"
 

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I'll let the Picture attached explain it all.

The picture explains an attitude that seems to exist all over the world.

Yeah your right, they are talented guitar players that's for sure, if you like that sort of thing of course.

I don't regularly listen to the music of either one, but a bunch of guys from work were getting together to go to the concert and I went along. It was worth going to once.

I played surf music in a crummy band in middle school and high school. I thought I was good. I went to a Monkeys concert in 1967 or 68 because my mother bought me a ticket (she liked that crap). I was astonished by the opening act. I decided that what I saw convinced me that I would never be a real guitar player, and I have never seen a better guitar player since. The bands name was the Jimi Hendrix Experience.
 
Hey, we have been moved! Maybe we can cheer up the not so popular *cough cough* Instruments and Amps section. Too many You Tube videos have sent us here, LOL, at this rate next stop is at The Lounge.

For the technical minded here's a freebie. A 6AU6 phase splitter. Cheap tube.

http://www.retrovox.com.au/rh0754pm7.pdf

Hey wdc, I share your sense of humor and I also like to stir the pot when things get too boring. Good luck with your amp. I agree with most of what you said so I'll stop the bitching (just for now). I have a habit of raising my handbag though so no promises for the future. No malice on my part just funny genes.
 
Speaking of youtube video's,

Why is it that this forum has not enabled the youtube tags for embedding rather than linking? It would sure save time not having to hop from site to site for Clips & Tips.

The link for GENERAL INTEREST / MUSICAL INSTRUMENTS on the home page is broken it goes nowhere.

Hey, your right, the musical instruments link is invalid. We have just entered an alternate dimension.

Oh,,, Whats that?
I saw something.

OH, Hear That?

Run, The Greys are coming.

No really, all kidding aside,
some people including musicians feel that guitar amps are as much instruments as guitars, basses and so on.
Maybe that was why we moved?
 
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I nominate SY


I thought Sy was already building? or did he drop out?

When ever I come here, I had always used a direct link to the
"Tubes category"
I rarely if ever visit other sections of this site/forum.
Since I am active in other music gear forums, I never really go into the instrument section over here since there is rarely much activity..
 
Tubelab seems upset...

Not upset. For some reason the company proxy server now classifies the diyAudio forum as "sports and entertainment" site. Occasional viewing is not forbidden but repeat visits are logged. I tend to be stuck in front of my work computer for about 10 hours a day.

I got a smart phone so I could have an unmonitored internet connection at work, but I could not find this thread today. I'm sure I will figure it out once the links are working.

If the thread goes into dead state probably not too happy.

This thread has provided the kick in the a$$ that I needed to finally make a guitar amp. I now have 4 different designs in the works and a few more sketched out on paper. Several designs are very strange twists on common circuits.

I have the majority of the parts to build the Fender Tweed Deluxe circuit. My goal is to use all cheap compactrons 2x6AY11 and 2x6T10. I am hoping the Triad N-68X based voltage double will be up to the task.

The N-68X has no problem running my 3 and 4 tube designs. The big guy just sucks the life out of the transformer. If you are going to build amps you need to get a Kill A Watt energy meter. Newegg puts them on sale for under $20 occasionally. It will measure the watts drawn and the VA drawn by any electrical appliance. Devices that use rectifiers feeding filter caps tend to draw energy in short pulses near the crest of the sine wave. This heats up the transformer. My rather non conventional circuitry draws 32 watts but consumes 48 VA. 48 VA is too much for the N-68X.
 
Hi guys,

My sincere apologies for the front page menu not updating after we made forum changes (everything was still accessible from the /forums/ page, fwiw). We implemented a cache for the menu about a year ago to speed the website up (it's stored as static HTML in a template) and when we made the forum changes last night, didn't notice the problem because as admins our menu is generated dynamically so it looked just dandy.

The menu will be repaired in the next few minutes - took us a while to get to the bottom of this.
 
Well, I spent last night trying to get rid of some of the excessive hum without much success.

I tried adding a 47uF filter cap to each stage one at a time to see if it might be PS ripple, and was not able to isolate any stage that was sensitive.

I tried swapping tubes, without effect other than making it worse.

I tried elevating the filament/heater supply with no measureable difference.

Based on these attempts at hum reduction, I've come to the conclusion it is layout related loops picking up ambient noise, and it is a characteristic of the breadboard construction tecnique. The only way I think I could have a major impact on hum would be to build the amp in a chassis where I could have better control of ground/power loops which pick up noise.

If I "dial it to 11", I get a local radio station to boot, although gain is around 2400 at this point and it only takes 2mV on the input to clip so it is not much good cranked this way.
 
Grumble...

I thought the challenge was to build a $100 tube amp. A $100 transistor amp is not much of a challenge, except getting decent sound out of it🙄

Now I have to navigate all the way over to this other place to read the thread.

What I wonder is who thought it was such a big deal to have that amp thread in the tubes forum? What was the problem? Was it annoying for disinterested parties to have to skip over the thread title? Or is it some kind of social engineering?

Oh well, the day is full of other more interesting pursuits anyway...
 
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We're just fertilizer for this new soil. I understand the reasons behind their decision, question is: will something grow on this remote land? I'm gonna sprinkle this patch everyday. Sit and wait. See if it grows or withers.