My first stripboard pedal build - a few questions....

TJT1979

Hi all

I've built plenty of PCB pedal kits before (Fuzzdog), as well as an Ampmaker P1800 amp. I wanted to try to build myself a Hudson Broadcast using stripboard (Veroboard).

What websites do you recommend in the UK for buying small quantities of components? I stumbled across Farnell and RS - any comments?

Secondly, I have a couple of questions on the caps. I am using the third layout on this page (no charge pump)...
http://tagboardeffects.blogspot.com/2016/12/hudson-electronics-broadcast.html

The 3 caps which are non-electrolytic.... what ARE they?

The rectangular yellow ones look like they're probably Polyester Film Capacitors? Like this...
http://uk.farnell.com/multicomp/mcpbsfc-1j102ka45/cap-film-1nf-63v-rad/dp/1685470
http://uk.farnell.com/kemet/r82dc3330dq60k/cap-film-aec-q200-0-33uf-63v-rad/dp/2763211

Correct?

And the little red round one, that looks like a ceramic disc. Not sure of differences between multilayer and disc&plate? I found these...
http://uk.farnell.com/walsin/rd20n331j500a5hand/capacitor-mlcc-np0-330pf-50v-rad/dp/2576681
http://uk.farnell.com/multicomp/mcbu5331k5/cap-mlcc-y5p-330pf-50v-rad/dp/9411763
Do they look right?

Thanks in advance for any help!

Cheers,
TJT

BigMonka

For small quantities of components I like to use bitsbox: https://www.bitsbox.co.uk/
They also have stripboard kits for various guitar effects (although not the hudson broadcast as far as I know)

english_bob

Have a read of the "components" page on Tagboardeffects - very helpful for these sorts of questions. From memory it doesn't matter what type of capacitors you use in terms of making the pedal work (or not...), but some are lower noise.

+1 for Bitsbox- their postage is cheap and they've generally had everything I've wanted for little stripboard builds. They almost certainly won't have the OC71 transistors though. Obsolete Ge transistors can get expensive if you don't have the wherewithal to test them at home. Best to get a pre-tested one with an hFE of 70+

randella

Another vote for Bitsbox.  I've been using them for years and they're very reliable.

TJT1979

Thanks for you replies - very helpful. I will check out Bitsbox and look for tested Ge transistors!

Cheers

Danny1969

Bright Components are a good supplier for small quantities, CPC and Mouser are good for larger quantities. Thing's your gonna use again and again like duel opamps are best brought in quantities of 10 as the price saving is substantial, common values of resistor like 10K and 100K are best brought by the 100, likewise 100N and 200N caps 

Different capacitors are good at different things ...... a ceramic cap for example is great for decoupling because although it only has a small amount of capacitance in comparison to a typical electrolytic it has a much lower ESR (equivalent series resistance) .....thus can react to dealing with dips quicker 
Generally for pedals your gonna come across 3 main types

Electrolytic for reservoir power supply and coupling between lower imedences down to very low frequencys  .... non polarised bi polar Electrolytic's are also available in lower values  and can be used for coupling 

Polyester caps and to a lesser extent polypropylene for general  audio coupling between stages  .... as most pedals use a single supply the opamps are generally biased at half of 9V meaning every stage needs to be coupled with a cap to stop the bias DC going into the next stage 

Ceramic caps for decoupling the supply in places like very close to the power pins of the opamp  .... in general I don't use these for coupling audio as they can generate noise themselves 

For prototype work I often use salvaged components from old radios, computer speakers, basically anything that uses easy to extract through hole components 

TJT1979

Thanks!

I've been looking at Ge transistors and it's definitely harder to find something well-tested that I'd expected.

I'm thinking of putting this on the backburner for the moment... just for parts I'm looking at 50-60 quid, and if there's a good chance it won't sound like the real thing, it's a lot of money to waste!

My idea was to have this as an always-on pedal in front of a clean SS amp (Quilter). Set it to a mid-crunch and then ride the guitar controls for cleaner sounds.

I will build myself a Sweet Honey Overdrive first and see how that goes. If it doesn't do what I want I'll see whether I try building a Broadcast, or save up for a real one...

Cheers.

tampaxboo

get 100x common value stuff from ebay china, and the little fiddly bits of uncommon values from bitsbox.
eg don't fanny around buying one resistor of this and one of that, it will take you forever and cost you tons more. instead buy one of these and get the odd 'awkward values' from bitsbox.

https://www.ebay.co.uk/itm/Mixed-300pcs-Component-Resistance-Pack-1-1-4W-Metal-Film-Resistor-10-1M-ohm/371320477351?epid=1588746061&hash=item56746cd6a7

you can buy a big bag of 50v specific value polarised 10u or 100u caps this way too.
https://www.ebay.co.uk/itm/100-Pcs-50V-10uF-Polarized-Aluminum-Electrolytic-Capacitors-5x11mm-R8U3/263200536418?epid=1469209198&hash=item3d47f97762
https://www.ebay.co.uk/itm/20pcs-100uF-50V-105C-Radial-Electrolytic-Capacitor-8x12MM-K6/292083670487?hash=item44018b1dd7:g:9tYAAOSw-YVXlYqn

things like 10u and 100u caps, all those listed value resistors in the pack will come up again and again if you start building, so it is worth getting a big bag when you can find them so cheap. as for £50-£60 for parts? no way.
your layout has 5x 10u and 7x 100u. packs above cover those with tons left over for other builds. most of the resistors will be in the kit. tick all those off and for £3 you have covered 75% of the vero components.
and when you come to build your next pedal you'll already have 90% of the resistors and a lot of the caps (everything has 10u and 100u), so your next build will be really cheap.

the most expensive bits will be the enclosure/jacks/3pdt stomp. but if you have an old joyo etc you don't like or use, you can repurpose it. empty it out and use that as your base.

where bitsbox are really good is in supplying the germanium fancy bits, unusual value caps, etc. Bob (at Bitsbox) knows his niche really well and has organised his business to focus on bits pedal and amp builders will be looking for.
he sources the best and his customer service is great. he tests his fancy bits too, so worth paying the bitsbox premium for interesting diodes and premium nos trannies.

but making pedals isn't so much about saving money, you can buy cheap stuff from china for £20 that you can't build cheaper than. it's far more about empowering yourself. and tailoring builds too your individual wants and needs. that's what it is there for.

so you can go to guitar layouts etc one wet bank holiday weekend, flick through the lists and say 'i'll have that one'... and then just freakin' make it, to your bespoke specs, with your own hands and talent.
doing things that make you feel proud of yourself is really good for the soul. and you can't buy that feeling for all the money in the world, you earn it. test of character! PMA!

aord43

I use Rapid for components, and Maplin for emergencies.  Also bundle bags of caps or resistors from ebay!

Octafish

Another vote for Bitsbox here , great service and very quick dispatch/delivery. I also use RS Components and Rapid Electronics, in particular for enclosures as they have a widest and best priced selection.

For Ge transistors I did try some of those sold by Bitsbox, but they're not tested and you take pot luck. I generally found the AC128K they sell to be good with low leakage and hFE in 55-75 range. I tried some of the others they sell, but most had high leakage and hFE. Alternatively Fuzzdog have some decent tested Ge Transistors for just £3-4 each also check out https://www.langrex.co.uk/.

If you have a multi-meter you can make an good little Ge tester using the tagboard design.  Most things I've read suggest that hFE and leakage is more key to the sound of a Ge build than worrying about mojo names such as OC71 or NKT275. It's always worth googling hard to find stuff along with the word 'alternative' or 'equivilant' as some bits had different names depending on the country whether it's military spec etc.

TJT1979 said:

Secondly, I have a couple of questions on the caps. I am using the third layout on this page (no charge pump)...
http://tagboardeffects.blogspot.com/2016/12/hudson-electronics-broadcast.html

The 3 caps which are non-electrolytic.... what ARE they?

As you guessed and others have confirmed they are two polyboxes and a ceramic. Generally ceramic are one of the few options for very low value capacitance. The polyboxes are good for compact layouts. You'll find Tagboards often suggest polyboxes on their layouts where space is limited.

Adam_MD

I like the 5 or 7mm height nichicon or panasonic electros It’s great having the extra clearance to work with as some electros can be quite tall.  

When I started and bought loads of cheap eBay electros and getting them to fit often meant laying them on their side.

TJT1979

OK, you guys have convinced me to go for it!


A couple more questions...

1. Instead of Polybox caps could I use either of the following?... Are metal film worse than poly film somehow? I am looking at these....

https://www.ebay.co.uk/itm/30value-450pcs-Polyester-poly-Film-Capacitors-Assortment-Kit-100V-5/171631325342
https://www.ebay.co.uk/itm/200-Pcs-630V-0-001uf-2-2uf-25-values-CBB-Metal-Film-Capacitors-Assortment-Kit/262633915805


2. Looking at the original schematic, can anyone figure out why it'd need an ON-OFF-ON switch? Looks like an ON-ON would work fine unless I'm misunderstanding something. Would there be a 3rd gain option in the middle with switch off??

http://tagboardeffects.blogspot.com/2016/12/hudson-electronics-broadcast.html



Lastly, a huge thanks for everyone's time & effort to post responses.

Adam_MD

Those metal film caps you linked will be huge they’re rated for 630v.  The greenies will work fine but there are a load of values in that you won’t use unless you’re planning on making a lot of different pedals.

aord43

One of the comments on that site suggests that the switch gives three gain settings, low, mid, high. I am not familiar with the circuit though so can't say for sure.