[AMP PARTS] Can I use small components for a amp head?

[Will.mendil]

Hi,

It's been a whilst since I posted here, glad to be back. Anyway, I had a question regarding the built of an amp, I know it's a bit off topic since you guys expertise in stompbox but I thought I'd still ask.  I've been wanting to build a tube amp from scratch copying a circuit from somewhere, surely ceriatone. I've been looking at the trainwreck which sounds great. You could buy the kit but it's nearly 1000$, and when I'm adding up the cost for just the electronics, it is much much cheaper ( I know you need to add the cost of tubes, chassis etc... but I want to build the amp in stages), but here's the thing. I've been getting parts from Tayda like most of us here which are great for pedals but they have nearly nothing for amps
(If somebody has a similar site for amps, I'll take it)
so I wondered if I could use these small parts to build the amp.
For example, if you look at this picture, you can see huge capacitors (orange), the blue capacitors are 25W tolerance when referencing to the layout. So I though I could use small disc ceramic capacitor that are 50W tolerant. Is that going to work ? I feel not but I don't know why. What do you think?

Cheers

[Metaldestroyer]

Yeah you could use the ceramics for the cathode resistor bypass caps, but ceramics are going to be noisier than electrolytics most of the time. For amp parts you should switch to Mouser or DigiKey. For dedicated amp parts, just do a google search for amp parts and you should come up with a few places if you feel you absolutely need orange drops, but you could almost certainly find cheaper options at Mouser.

[Luke51411]

The voltage is what is going to matter. You will need at least 450V-600V rated for some of the caps and depending on the build you will need some resistors in the 1W up to 5W ratings. I like tayda but I wouldn't trust any of their stuff in an amp build. Small leads are fine when they are going through a hole to get soldered but running on turret build... Also I wouldn't trust that their  components are in spec and actually can handle the power that they state. In a stompbox, sure. What do you have to loose? You're dealing with 9-18V typically Most of the components are going to be rated quite a bit higher than that anyway. For an amp build you want better quality parts.

[Will.mendil]

yeah, I guess you guys a right, however, finding these parts is much harder than it seems. Because I live in France, I can find tones of US shops but the shipping cost is just outrageous. there's a site called RS-online.com I don't know where they ship but they got good stuff and in France at least it's free shipping after 30€.

Anyway  I just wondered appart from the quality, why would you need big components, when the small ones are in spec. I guess the noise answer is a good reason

and finally, I do realise that power capacitor that need to handle 450V need to have mass. I was refereing to the board components

[Will.mendil]

What's the minimum power (watts) that you'd recommend for turret board resistors? 2W? 1W?

[Luke51411]

What's the minimum power (watts) that you'd recommend for turret board resistors? 2W? 1W?

Well the ones that aren't specified might actually be 1/4 watt, I'd want to verify that first. As long as they are withing called for specs, there is no reason you couldn't use the components you mentioned. Personally I wouldn't but that's just my opinion.

[Metaldestroyer]

Most resistors are fine at 1/4 watt, but many people use half watt resistors all around. Plate resistors are usually 1 watt, and power supply resistors as well as power amp screen grid stoppers are 2-5 watts. Use ohms law or what is specified on the schematic for safe tolerances here. Power filter capacitor voltage will depend on the power tubes you use, but are usually 450+ volts. Cathode resistor bypass capacitors are usually 25v and for the film caps throughout it depends on the position.

Farnell may be a good option for components? I know very little about European suppliers.

[Will.mendil]

Farnell is like mouser, as someone said on another thread, they kill you on the shipping. They are good if you are looking to buy a lot. but for 2 caps, lol....
Anyway thanks for the andvice. I have no idea when I'll get this done, but I'll be sure to post it online, might be next year though :p

[GibsonGM]

The layout diagram specifies the required wattage!  If none is given assume 1/2W, which are easier to handle and "look better" than 1/4W (altho the 1/4 would be fine in some places such as cathode bypass).   

There must be some other Europeans who buy parts on this forum, who could help you out with a supplier, no?

[Will.mendil]

I guess there might be, but they would need to show themselves

Looking at the pictures, how much voltes do you recon, the orange caps can carry

[Ice-9]

RS online is great for your parts. They are a major supplier of all electronic parts, YOU need to know what you want to order though. they are not a hobby amp/pedal parts supplier. I use RS a lot in England, other euro supplies to try would be Rapid online, and for more dedicated to amps and effects you could try musikding and banzai in Germany.

[Will.mendil]

I'll look it up, cheers

Looking at the pictures, what tension do you recon the orange caps are?

[bool]

some of them look like 630-volters

[davent]

yeah, I guess you guys a right, however, finding these parts is much harder than it seems. Because I live in France, I can find tones of US shops but the shipping cost is just outrageous. there's a site called RS-online.com I don't know where they ship but they got good stuff and in France at least it's free shipping after 30€.

Anyway  I just wondered appart from the quality, why would you need big components, when the small ones are in spec. I guess the noise answer is a good reason

and finally, I do realise that power capacitor that need to handle 450V need to have mass. I was refereing to the board components

Tubelectron who posts on here, posted a bunch of super nice amps over on Amp Garage recently, he's in France, see if you can track him down for tips on sourcing parts.

One of his many. May have to register to see pictures...

http://ampgarage.com/forum/viewtopic.php?t=27777

[thomasha]

Hi, maybe you can buy some stuff from banzaimusic or tube-town, or musikding.
This are some stores I found in Germany when I lived there, I guess that it's close enough.
I'm in Brazil, and Banzai even with oversea shipping, is way cheaper than Mouser...

[GibsonGM]

some of them look like 630-volters

Have to agree. If you look at 'where they go', you see that at least 1 goes to a plate, and you see the "B+4" connection...high voltage.    You can never go wrong in using those lovely 630V units    
Unless you're running some insane B+, of course!

[davent]

Bill of Materials for an Express in here from 2009. The basic parts to get an amp up and running, sourced from multiple sources so multiple shipping costs, not including shipping over $625US in 2009.

Not to mention, by all reports a super daunting/sensitive amp to build and get working properly.

http://ampgarage.com/forum/viewtopic.php?t=5691

[PRR]

> Can I use small components for a amp head?

A tube in an amp works with 10 times the Voltage and Power as a transistor in a pedal. You can't use midget parts.

> huge capacitors (orange), the blue capacitors are 25W

Learn the names of parts; it will help you shop.

The "blue" caps are electrolytic. The ones on board are probably cathode bypass, 10uFd at >5V. You can not get 10uFd in a ceramic disk (and if you did, it would distort). 10uFd 25V electrolytics *should* be in Tayda's catalog.

The "orange" caps are plate-coupling and *must* stand over 400V at start-up, maybe "only" 300V all the time the amp runs. The pictured type is "Orange Drop", a classic USA part, super high quality but expensive. There are a dozen other brands of HIGH-voltage film caps, though maybe not at Tayda.

Cathode resistors will be 1K or 1.5K with 1V or 2V across. Do the math. You need at least 0.004 Watts. Tayda can sell you these. Plate resistors will be 100K with 100V across them normally, but 300V when things go wrong. You *really* want 1 Watt parts here. Yes, you see 1/2W parts in many cheap imported amps with 30-day warranty. But DIY means you will keep it forever and do all your own repairs. Start with a part which will last a lifetime.

> I live in France

One Euro-market site which specializes in tube guitar amp parts is
Tube Amp Doctor Musikhandels GmbH
http://www.tubeampdoctor.com/
Deutsch or English top-right

They have Orange-Drops; they also have "mustard caps" which were/are widely used in tube guitar amps.

I have no affiliation with TAD and have never ordered from them.

$1,000 is not obscene for a complete amp kit. I was $600 into a Champ (2 tubes) before my life changed (didn't finish it). If you "want a tube amp", you can buy a mass-produced one from China a lot cheaper than you can buy the parts. It really helps to work near where the parts are made, buy thousands of parts at a time, and have contracts with stores.

[JustinFun]

Will, I hope you don't mind me saying this but it really doesn't sound like you have enough knowledge to start building with high voltage. It's not like making a pedal where you can just follow a layout - you really need to understand what each part does and why it goes where it goes. Getting it wrong on a 9v pedal just means it won't work - getting it wrong on a tube amp could be extremely dangerous.

If you want to carry on I'd suggest spending some time on one of the tube amp diy sites, and starting with a simple 1w two-tube single ended amp. It'll still be high voltage but with fewer parts it's harder to make a mistake. Make sure you understand the different parts of the schematic and what they do before you start to build. Work your way up to something bigger - transformers for high watt amps are not cheap, but on a 1 watter you can get away with some much cheaper alternatives.

[J0K3RX]

Get a cheap tube amp and cannibalize it for parts or just modify it. I got a brand new Jet City JCA20H for $159.00 free shipping and it will be a mean ass something or other when I am finished... Saw a Nady GTH 100 watt head for $100 on craigslist (didn't even know they made an amp) and turns out it's basically a JCM800.. Of course, somebody beat me to it