How it works

[Jarvini]

Thanks enzo I am slowly learning sometimes the hard way getting burned with overpriced unneeded items but I do listen to the advice I'm given and won't make the same mistakes twice!! We never had much money when I was young and so most of the things I had were either things I had found and repaired or just made and I've kind of always carried on like that as I get pleasure using the skills I have learned along the way, now I'm older I have my own little workshop in my garden literally full of all kinds of tools needed for pretty much any project or repair that I need to do and being a dustman you'll be amazed at what people throw away just because of a simple fault that given a little amount of skill and the right tools can easily be repaired (I do this regularly by the way) and as I have now turned to building my own amp i can't help but ask questions in order to further my knowledge on the subject as without it, it could quite easily become the last project I ever do and end up frying myself in my workshop!!
I've been looking at some gold plated transformer screws what do you reckon?..... ONLY KIDDING......
Scott

[g1]

Ok, in post #14, you mentioned quality and reliability. This is different than 'tone' and you won't get as much argument.
I like the automotive analogy, let's stick with it. Chrome in the engine bay will not alter much in the reliability department. Pistons made by a reputable brand compared to a cheap asian knock-off will. So there are places where you can make a difference in terms of quality and reliability, as long as we don't expect major tonal magic.
Someone I know works in the motorcycle industry. He told me when in doubt, stick with upper-midrange quality stuff. I fall back on that when I need to and it has usually served me well, regardless of whether motorcycle related or not. It's not 100% foolproof, but seems ok as a general rule.

[Chuck H]

To be perfectly fair, Juan is being a tad stringent. I'm sure he's done exactly this more than I have, but it's been my experience (as a competent builder ) that two amps that are the same schematically but different physically can indeed sound different due to minor phase errors caused by layout and lead proximity. But it's not a "this is a different amp" difference. It's not even the same difference you would get with a speaker change. So, short of building to a schematic and having incompetent design issues like gross phase errors due to layout and lead dress, Juan is fundamentally correct. And asking the same question different ways won't change the real answer.

That doesn't mean boutique builders are shysters Juan But it does mean that in the case of vintage designs what you are paying extra for in a boutique build would have to be limited to quality of materials, perhaps even parts made to spec just for the builder that other cloners can't get, quality of workmanship, perhaps an excellent warranty and definitely reputation, which amounts to product sound quality, reliability and support. These aren't insignificant things.

[eschertron]

I am building it to play it and as such I want it to be built as good as I can possibly build it knowing that I have used the best parts I could afford

Hopefully you've listened to the other posts about 'good enough' versus 'overpriced'. There are a lot of components out there that you do not want to buy simply because they are the most expensive. So without further clarification,

best parts I could afford

becomes an invitation to throw money into an ever-growing hole.

For my curiousity, is this your first amp, or is this the only amp you'll ever build? I can see the temptation to sink lots of money into the pride of having high-quality components; stick with reliable, well-thought-of parts, and you'll have the cash to build more than one amp, or build a guitar too! Keep posting on your progress, there is help here even if it sometimes sounds gruff and pedantic

[Jarvini]

It's my first amp so I picked a pretty simple one just one preamp tube, one power tube and a rectifier tube, volume and tone controls it does have a boost switch which works in conjunction with the cathode bias resistor but that's all and if it's a success then I'll try something a bit more complex but i wanted to start at the bottom so to speak and see how I get on I'm going to have loads of parts and wire left when it's done so I'll be well on my way if I do! I have had nothing but help on this forum to be honest which is brilliant I was just worried that I had got on people's nerves asking the same thing over and over I think I am trying to apply what applies to hi-fi as I have spent lots of time building my stereo, older amps and cd players speakers speaker cables and interconnects racking speaker placement and apart from loudspeaker choice none of it really applies to guitar amps it seems so I'm kinda in the dark, I need to get it built and go from there

[Chuck H]

I think I am trying to apply what applies to hi-fi as I have spent lots of time building my stereo, older amps and cd players speakers speaker cables and interconnects racking speaker placement and apart from loudspeaker choice none of it really applies to guitar amps it seems

What part of your experience doesn't apply? Did you learn (incorrectly) that the same stereo/hifi amp schematic built by two different people will sound different? All the reasons that make it a misnomer for guitar amps also apply to hifi amps. Everything else you mention culminates, at the very least, in a physical skill and experience set will surely help you on your guitar amp build. Even your experience sourcing parts will get you through that chore more quickly.

Stick around. Build your amp. Bring questions here.

[Jarvini]

Sorry by building I meant compiling I was referring more to the difference that a set of interconnects can make between an amp and a CD player or how one set of speaker cables can influence bass response or treble clarity.
This is how far I've got at the moment with my amp build apart from a collection of all the other parts that is

Nothing has been soldered yet just in case

[Tom Phillips]

Hi Scott,
It is prudent to keep in mind that the laws of physics apply equally to the electronics in a guitar amp, a high end stereo and all manor of other electronic devices. Once you understand the basic principles then you can apply them to construct the device the suites your need. As you learn the basic principles it will free you to be creative and to understand why things are done a particular way.

Attached is an annotated version of your turret board. The added note is there because elevated temperatures shorten the life of electrolytic capacitors. Your layout has an electrolytic cap right next to a power resistor that will heat up as the resistor does its job. Your layout will not affect the initial performance of the amp but it will shorten it's useful life. This is just one of the many things you will learn as your electronics studies progress.

S...or how one set of speaker cables can influence bass response or treble clarity...

Warning. That is pretty much snake oil that is propagated by people who want to sell expensive cables. There is a well known blind test that was done comparing high end speaker cables to plane old coat hanger wire. The story is that the golden ear audiophiles could not tell the difference. Ha!
Cheers,
Tom

[Chuck H]

I was referring more to the difference that a set of interconnects can make between an amp and a CD player

Oh. You mean, like gold contacts and cryo treated copper? (Sorry, you'll get nothing but grief here for that stuff )

or how one set of speaker cables can influence bass response or treble clarity.

The reason you don't hear about this with guitar amps is that the cable runs to the speaker are typically very short. But LF, even for a guitar amp, can very much be affected by long speaker cables of small conductor.

As to your layout so far... There are indeed some less than ideal things going on. But this is not just WRT guitar amps. That is, they would be less than ideal in a hifi amp (or even a CD player).

First I'd like to ask if your assortment of resistor types is intentional for their reputed tonal contribution to specific circuits or just what you had on hand in those values.?. I'll guess the former based on the silver plate wire and the TAD caps Grow a thick skin, you're going to get ribbed here sometimes... If we like you But really, the tonal contribution of carbon comp resistors is going to be too small to hear. What won't be too small to hear is the shot noise typical of carbon comp resistors. They are the worst type of resistor for this sort of thing and the worst place to use them would be high voltage dropping resistors, like plate load resistors. Shot noise is, if I've interpreted it correctly, tiny arcs of electricity crossing voids in the resistive element. The end result is a kind hissy sound that borders on crackly. It's especially apparent in higher gain circuits though, so you should be fine with this build using them.

Then there's the grounding. Right now you have the power tube cathode resistor intentionally grounded with the preamp. That's a no no. You REALLY want to keep high current power amp and power supply grounds OFF the preamp ground buss. Since you've already cut the board you may need to get creative to alter the layout, but that's not the end of it...

Right now you have the cathode bypass cap physically close and parallel to the cathode resistor. Electrolytic caps HATE heat. That resistor makes a lot. Although this "parallel on two eyelets or turrets" arrangement is common that is likely the reason failure of that cap is common in vintage style amps. Most experienced techs and builders don't do it. Preferring to mount the cap away from the resistor, but ground it in the same place.

And that's all I can tell from what you have so far.

[Jarvini]

Glad I put the picture up before soldering now !! Looks like some adjustments are needed don't worry I can take a good ribbing and I was expecting some errors with regard to the cathode bypass and electrolytic issue I take it you mean the one for the power tube that I need to alter the grounding for ?
Really helpful advice though thanks chuck