NKT213's

[PorkyPrimeCut]

Hi,

Yet another fuzz pedal build (it's becoming a sickness). This time a Burns Buzzaround clone.

Can anyone suggest a good place to buy theall important NKT213 transistors?
I'm looking at around £10 each at the moment. Kinda steep. Maybe I've missed somewhere (or someone?)

As you might've gathered, I'm in the UK.

[midwayfair]

Gee, you actually found some? Is it a high-rated seller? Are they tested, and do they tell you the test results, or are you expected to take their word for it that it's a decent transistor? Are they trying to sell you a set for the buzzaround, or do you need to take your chances and buy several?

This is a rare transistor. I don't think I would trust anyone trying to sell me some unless I was able to test them in person.

There's no reason to justify the expense of something rare -- you can build it with any halfway decent set tested for a Tonebender MKIII. They're very similar topologies. Also, Smallbear sells a matched Buzzaround set for a mere $15: http://www.smallbearelec.com/servlet/Detail?no=1272.

[PorkyPrimeCut]

I know of one place that seems to stock them.

I tried one that a friend made recently & I'm utterly smitten.
I've had pretty bad luck with fuzz builds, partly due to my lack of technical knowledge when it comes to biasing circuits.

This time around (call it 4th time lucky) I want to try & go down as close a path to the original as I can.
I'm hoping I'll be able to test the ones I've sourced before I buy them but who knows if they'll let me.

[midwayfair]

as close a path to the original as I can.

Then you need to find out the gain and leakage characteristics and voltages of a vintage unit, which will allow you to approximately duplicate the original construction.

Part numbers don't have a sound. While it's true that some germanium transistors might be MORE LIKELY to have certain gain and leakage characteristics, and it's true that there is a difference between the sound of NPN and PNP transistors, the number written on the case is often meaningless except to give you a fairly wide range of expected behaviors. New Market was just a brand; there may be dozens of other part number markings that overlap the transistors' characteristics.

What I'm trying to warn you about in my post is that you are buying something that is rare, sought after, marked up, and consequently in danger of being counterfeit. I mean, if your friend built himself a fuzz with L30 worth of transistors from the same place you are looking at and came up with a good fuzz, that's great, and maybe that amount of cash is worth it to you. But you need to be aware that you're paying at least 3x as much as you need to to get a good sounding set of transistors. You could buy bulk lots of other less rare parts and make yourself a dozen fuzzes with that kind of cash. You'd also learn how to test transistors and have enough extra parts to experiment with gain and leakage characteristics in the Buzzaround. (For instance, I ended up with something very different from the stock transistor ranges.)

I mean, do what you want, and it's no skin off my back, but I'm just trying to help you out. Giving credence to mojo is not a good way to learn anything about the circuits you're building, and a good way to blow cash and get taken advantage of.

EDIT: There's not even a compelling reason to use three of the same part. The first two transistors in the buzzaround are just an input stage and form a Darlington transistor. Almost nothing in the way of distortion characteristics there unless your input signal is huge. Not really much reason even in using germanium there except that you need somewhat low gain, which might be hard to find in silicon.

[PorkyPrimeCut]

I appreciate you being straight to the point. Believe me, you're not the first person to warn me about mojo!!

The supplier is the same place that sold my friend his NKT's (unfortunately, that was 2 years ago & they've doubled in price). I just spoke with them & they're tested & guaranteed. It actually looks as though they stock all the other assorted bits & pieces that I'll need for the circuit so, in a way, I save a little cash by getting it all posted in one go.

....can you tell I'm trying to justify my madness here? Hehehehe!!......

I'm hoping this pedal will be a keeper, and put an end to my fuzz pedal building obsession. If it doesn't work out I'll hopefully be able to sell it on to some sucker someone who appreciates the finities of spending way too much on old, obsolete parts.

[Jaicen_solo]

Can't help you with the NKT's to be honest, I just buy whatever I can find and hopefully find some that work well for me.

DO you have a link to the Burns Buzz-Around schem? I hear it was Fripp's fuzz of choice, despite the fact that he would always say, 'any fuzztone will do' in interviews.

O/T, but I was a talk by Fripp at my university a few years ago. The man can destroy all your dreams in one short sentence. Still a hero to me.

[PorkyPrimeCut]

The layout diagram my friend used is here.

Next time I see him I'll ask if he followed an actual schematic aswell.

[LucifersTrip]

The schematic's all around the www



Have you considered a TB MKIII or MKIV?  Q1 & Q2 is the same, just as easy. You can use hfe as low as 30 - 40, but Q3 is easier to get right on the MKIII and MKIV since you can easily screw with the collector resistor.  Also, the controls are "better", since you won't have to deal with big volume changes with timbre change as on the BB.

[PorkyPrimeCut]

Have you considered a TB MKIII or MKIV?...

I built a ToneBender MkIII using the MadBean Pasty Face PCB but something didn't work out right. I don't know why but it just really lacked something.
I'm aware of the similarities and might actually butcher the ToneBender & turn it into a BuzzBender (ToneBender enclosure & knobs with Buzzaround innards).
I kind of have my eye on another style of enclosure though so I might sell or troubleshoot the Tonebender.

I'm certainly not new to fuzz builds but funnily enough, my favourite one is still the first, a BYOC - ESV Tonebender MkII which recently got rehoused...


Sheet steel enclosure. Letraset type over copper Hammerite. Enamel clearcoat. It couldn't have turned out better.

I sold a D*A*M 1966 for silly money, bought the BYOC and realised they sounded identical!! The remaining money I had left went into 3 other pedals.
You'd have though that would've been the ultimate lesson in not getting seduced by mojo. Clearly not!

[jdub]

+1 to what these guys are saying.  FWIW, I built my Buzzaround using 2SB175s that I got for a buck and a half apiece and it sounds fantastic...

[digi2t]

+1 to what these guys are saying.  FWIW, I built my Buzzaround using 2SB175s that I got for a buck and a half apiece and it sounds fantastic...

+1 on the 2SB's, and Russian MP20B's work well too. I did a write up on this, including videos of both types of transistors, here;
http://www.diystompboxes.com/smfforum/index.php?topic=96991.0

[Bret608]

I've got a Buzzaround made by Ghost Effects in the UK that has NKT 214s, about as close as you can get to the 213s. Don't get me wrong, it sounds great; but I bought this before I knew how to test Ge trannies myself. I haven't actually built a Buzzaround, but based on my experience with a Fuzz Face and a MkII I did recently, it can be pretty rewarding to test and try out different transistors until you get the sound you want. I really like 2n1305s for PNP and 2n1304 or 2n1306 for NPN. These sound great but aren't such a "name" transistor that they'll cost you a wad.

[PorkyPrimeCut]

I pulled the trigger an hour or so ago. Just couldn't resist!!
I'm sure I'll be able to sell them on at a later date & make my money back so I'm not fussed about the expense.

My old multimeter had one of those 4-holed HFE testers (I think that's what it was) but mysteriously went missing.
I bought a pocket-sized replacement but didn't think to make sure it had the same feature.

Nowadays it'd be pretty useful so I might buy another one.

[digi2t]

My old multimeter had one of those 4-holed HFE testers (I think that's what it was) but mysteriously went missing.
I bought a pocket-sized replacement but didn't think to make sure it had the same feature.

Those are useless where germanium transistors are concerned. They do not take into account leakage, hence giving you false readings.

Your best bet is to use the transistor testing procedure as outlined here;

http://www.geofex.com/Article_Folders/ffselect.htm

Or, get a Peak Atlas tester.

[PorkyPrimeCut]

My old multimeter had one of those 4-holed HFE testers (I think that's what it was) but mysteriously went missing.
I bought a pocket-sized replacement but didn't think to make sure it had the same feature.

Those are useless where germanium transistors are concerned. They do not take into account leakage, hence giving you false readings.

Your best bet is to use the transistor testing procedure as outlined here;

http://www.geofex.com/Article_Folders/ffselect.htm

Neat! I'll be sure to try this out when my stupidly expensive transistors arrived.

[LucifersTrip]

I've got a Buzzaround made by Ghost Effects in the UK that has NKT 214s, about as close as you can get to the 213s. Don't get me wrong, it sounds great;

that would be great if you (or anyone) could post voltages of ones that sound cool. it would be helpful for anyone who's about to build one.

for instance, on my last one I had Q1/2C at -5.1V and Q3C at -2.74V

again, that's just a starting point. do the rest by ear. I highly suggest  trying Q3 with MANY different leakages. the results will vary....alot!
that's why I always find it funny when someone says this or that sounds great with 2NXXX's or 2SBXXX's. Honestly, those statements have very little meaning without the accompanying hfe's and leakages. 

also, screw with the collector resistor on the Q1/2 darlington pair.  for instance, I had to increase that a bit (to 18K) when experimenting with Q1/2's in the low (Q1: 32/ Q2: 34) hfe range. remember, choose Q1/2 with the lowest leakages since leakage is multiplied in a darlington formation.

anyway, have blast

[PorkyPrimeCut]

Can someone point me in the right direction of a shielded wire supplier, preferably in the UK.

EDIT - I'm starting to think it might just me ordinary patch cable.
When I do a search for "shielded patch cable" in eBay I get loads of auctions for internet cable. Can I just use that?

[bluebunny]

Can someone point me in the right direction of a shielded wire supplier, preferably in the UK.

Bitsbox has various flavours of screened cable (and lots of other dead-useful stuff, if you've not come across them before).  Highly recommended.

[duck_arse]

I'm certainly not new to fuzz builds but funnily enough, my favourite one is still the first, a BYOC - ESV Tonebender MkII which recently got rehoused...


Sheet steel enclosure. Letraset type over copper Hammerite. Enamel clearcoat. It couldn't have turned out better.

porky, what happened to that case? why're the sides got that little split?

+1 to what these guys are saying.  FWIW, I built my Buzzaround using 2SB175s that I got for a buck and a half apiece and it sounds fantastic...

2sb175 you say? I got me some of them laying about. like I need another fuzz circuit at the moment.

[PorkyPrimeCut]

I'm certainly not new to fuzz builds but funnily enough, my favourite one is still the first, a BYOC - ESV Tonebender MkII which recently got rehoused...


Sheet steel enclosure. Letraset type over copper Hammerite. Enamel clearcoat. It couldn't have turned out better.

porky, what happened to that case? why're the sides got that little split?

I thought about that myself. From a design perspective there's no reason why it should be there...but it is...ah well.

Still, they're amazingly well made enclosures. Way heavier than aluminium enclosures but pretty much identical in dimensions to the Shin-ei Superfuzz enclosure except for the concaved control knobs section on the side). I bought mine from a European eBay seller who had 4 more. I should've bought the lot & by the time I realised this someone else had beaten me to them.
If you fancy giving them a try this guy sells them in the US. Good luck with questions though. I've messaged him several times & haven't had a single reply. Great salesman...not.