Alright, back to the normal layouts. Here's a really unique overdrive pedal from Hudson Electronics in the UK. It features an onboard charge pump to take 9 volts up to 24, so be sure to use appropriately rated capacitors (min 35v for electros). The transformer (the big yellow thing on the board) can be found on Mouser and other online vendors. Because of the transformer I suggest building this in a 125B for the extra height. Here's the schematic for reference. From the Hudson Electronics description:
The Broadcast is a transformer coupled, discrete Class-A germanium pre-amplifier based on the classic broadcast consoles of the 1960s. In the low-gain setting, the Broadcast can cover everything from sparkling clean boost through to transparent overdrive, all with a healthy dose of volume available to push your amp. The Broadcast features a specially selected Triad steel-core transformer and a NOS germanium transistor. Advancing the gain on the Broadcast starts to saturate the transformer and the pedal’s discrete circuitry, giving rise to a gentle and dynamic compression coupled with subtle thickening of the midrange. With the gain switch in the high setting and the trim control wound up, the Broadcast starts to deliver heavier distorted sounds with a warm and fuzzy edge to them. The Broadcast covers a wide range of driven and distorted tones whilst remaining dynamic, responding well to pick attack and the subtle nuances of every player.
I cannot agree if this one is "normal" one. LoL
ReplyDeleteNormal layout style maybe? haha
DeleteLol, dude, I've ordered 3 transformers from ebay yesterday because I was totally sure it won't take you long to make this layout :D
ReplyDeletehaha I love it!
Deletehi, is the schematic available? thanks!!
ReplyDeleteYep, here you go!
Deletehttp://imgur.com/a/DGm2k
thanks a lot!!
DeleteSo far in the 18 months of building pedals, it's been all PCBs. How difficult of a project would this be for a first time bread-boarder type thing?
ReplyDeleteOr do you sell a PCB version of this?
DeleteBreadboarding or building on perfboard? If breadboarding, have at it. Breadboarding is the type of thing you can easily fix any mistakes as well as experiment. If perfboard, I would try something a little simpler to cut your teeth on. I could make you PCB, though note that the layout has not yet been verified. Shoot me an email if you want a PCB (gehringcustomguitars (at) gmail.com)
DeleteFriend: I checked this circuit. Thank you for your work!
ReplyDelete
DeleteIT WORKS LAYAUT!
Awesome! Thanks for verifying
DeleteThe layout shows a 470uf electrolytic across the output from the charge pump to ground - but in the schematic it is shown as 120uf - why is this, and what difference will it make?
ReplyDeleteIn the schematic there's actually 2, 120uF caps in the schematic. These capacitors are for power filtering, so I put in a 470uF in the layout to be safe. You can try different values if you want.
DeleteThere’s actually 3 120uF caps, but on other layouts they switch the one closest to the pump to a 10uF cap…
DeleteThis circuit I did not start until I joined all the components, which are neither easy to find nor cheap. The capacitors put a nichicon, the 470uf eventually got lost in the post office, and I ended up replacing it with a 330uf, and I think there is not much difference, the transformer Triad Magnetics, and the transistor was more complicated, the price that ask for the OC71 is excessive, I tested with the ones I had here, and I chose the TG-5S (HFE100) I think it's from Poland. Sound is not easy to understand at first audition, it may even be a little disappointed. What stands out soon is the absolute silence, no background noise is heard, it's really class A amplifier, the pedal is presented as a booster, but the gain is not very high, at least in my case I find it much more weak that most of the other boosters I've tested, but (there's always a "but" on this pedal) the bandwidth that comes out of this pedal is too big that it seems we heard the guitar breathing, the overdrive with the transistor I used was very smooth, but it was to realize that even though not knowing much of electronica, there is a division of the sound a clean part direct to the output, and another goes through the transistor just to give a scent. After you start playing, you become addicted to the sound, and you can not stop.
ReplyDeleteThe circuit is as always, five stars, my transformer had to bend its legs, because the space between them is another 4mm. I have not tested it yet with other effects, but I think it should sit very well at the beginning of the chain with the clean adjustments, leaving a trail of magic!
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ReplyDeleteWhere can I find a switch like Hudson uses? It has two connections and is pretty heavy duty looking. How do I use a switch with three connections, or can I even use that?
ReplyDeleteAll the gut shots I've seen of Hudson pedals have a pretty standard 3PDT footswitch... You talking about a Carling switch?
DeleteLook at the inside image here. It has the model and make and I still can't find it anywhere: https://reverb.com/au/item/2134518-hudson-electronics-broadcast-original-run-with-nos-transistor
DeleteIt's the gain switch I'm talking about.
DeleteAh. I've seen heavier duty switches like that on Amazon and eBay before. Not sure on the specific brand or anything tho. Just search for heavy duty switch. You should get some options that way.
DeleteHow to wire switches with more than two connections is what I'm not sure about.
DeleteCheck out the General Layout Notes tab and look for the switch numbering diagram.
DeleteI bought one like in this link. The three connections are numbered. I assume I just hook them up to the corresponding links in the diagram above?
DeleteCorrect. Should work fine.
DeleteThanks for you patience and help...and great layouts.
DeleteLink: http://www.homedepot.com/p/Gardner-Bender-20-Amp-Single-Pole-Toggle-Switch-1-Pack-GSW-13/100122325
ReplyDeleteHow can I wire a 3pdt switch to change between low gain and high gain, and also wire a second level pot to control the low gain level and high gain level independently?
ReplyDeleteLike this version:
https://andertons.scdn2.secure.raxcdn.com/2/1/images/catalog/i/xl_133893-tmpB018.jpg
I'd love to know this too!
Deleteits very simple to do. 3pdt switch flick between two volume 25k pots. 3 pin potentiometers going through 3pdt to exit transformer. Find photo hudson electronics broadcast dual switch inside< & you will see it.
Deletehttps://imgur.com/55GF7bh
DeleteThe TY-141P layout is confusing me. What pin# does the black dot on top of the transformer correspond to? It can't be #1 or it would have to be put in from the other side of the board.
ReplyDeleteHi!
DeleteTY-141p is 1:1 signal transformer, you can solder it both ways, since his windings are identical.
Thanks for the response. Still can't get it to work but you cleared one thing up. lol
DeleteDoes anybody has BoM? Please
ReplyDeleteThere is a mistake in gain pots. Check it.
ReplyDeleteThe mistake is that the resistor 5.6k is in parallel with gain pots.
DeletePlease, correct the layout
ReplyDeletehello, I built this pedal and my gain pot is acting strangly.Do you mean to say that 5.6 k connected to 1 0n gain pot and the other lead to 1nf as well as 3 on gain pot ? (or perhaps 2) the pedal seems to be working fine other than it is quite and only works with the gain knob at counterclockwise (I tried soldering the pot the other way around and it still only works counterclockwise)
ReplyDeleteYou can try to use gain pot 3. You need to place 1nf between the gain pot 1 and the gain pot 2, then resistor 5.6k and pot 3 connect together. Connect potentiometer to pots 3 and 2 (pot 1 is not used for potentiometer).
DeleteThank you very much for your response. i am having some trouble understanding. If I took a potentiometer and soldered 1nf between lug 1 and 2 and a 5.6k from lug 3 to the board and then soldered lug 2 to the board as well, would this be accurate? Part of your advice that confused me is you say to connect the potentiometer to lugs 2 and 3 of the potentiometer. If you mean to say connect lugs 2 and 3 to the board, where it says gain 2 and gain 3 on the board, this also confuses me. In that case lug 3 would be connected to nothing and lug 1 would also not be connected to the board. Note that gain 3 on the board is closest to the Corner and is not connected to any trace. Your help is greatly appreciated, as I would not have been able to find the mistake on my own. Perhaps you could clarify response by using the terms lug 1, 2, 3 for the potentiometer and board gain 1, 2,3 for traces on the board.
DeleteMaybe someone can help me diagnose my problem. I switch it on and there is a volume drop (that isn't an overdrive then dude! lol). The middle switch position is the loudest though still lower than the uneffected signal. To the right, it's slightly lower and to the left, much lower still. The knobs seem to function as they should but the overall volume just isn't coming out. Any ideas?
ReplyDeleteI've had the same problem and I think I may have found the solution, though I haven't had the time to apply it. First of all, there is a mistake with the way the 5.6k and 1nf are connected to the gain pot, as per the conversation above. You can check the schematic or I can try to describe more clearly. the other thing I've just realized is that the germanium transistoris a PNP, not an NPN as I had assumed
DeleteI can't wait to fix it as I've been troubleshooting this pedal 5ever.
I'll sure be interested to hear how it turns out for you. BTW, are you using an OC71 as suggested or did you find a suitable replacement?
Deleteits working! this is definitely a moral booster. this pedal is very loud so you'll for sure when its working. I used TI 2N1303 PNP Ge. I think any pnp germanium will work. the 1nf cap goes between gain 1 and gain 2. gain 2 on the board goes to gain 2 on the potentiometer. 5.6 k goes in series between gain 1 on the board and gain one on the pot.
DeleteI can send you a couple of the PNPs by mail if you like, just shoot me an email.
DeleteGreat! Glad you got yours going. I'll try your suggestions in the next few days when I get a chance. I appreciate the offer of the PNPs. What is your email?
ReplyDeleteEgoldsbo@gmail.com
DeleteI did finally get mine to work and while it sounds good, it doesn't get anywhere near the gain I was expecting. The videos I've seen have it getting downright fuzzy at the upper limit of the gain pot. Mine isn't making it there. So, two steps up and one step back for me at the moment, but I'm still working on it.
ReplyDeleteDid you use the 15v diode?
DeleteI'd start by checking the voltages on the op amp and the transistor
DeleteAlsp, you could try to run it at the end of your pedal chain and increase the volume being inputted. I had mine at the beginning, but I found it worked better right before my amp
DeleteHey all, I got this thing working and love the sound, but I'm still having some louder than usual switch popping issues. I added a 1M pulldown resistor from the board out to ground to match the one on the input - any other suggestions?
ReplyDeleteI am having the same issue
DeleteSame for me. Did someone solve the problem ?
DeleteI have an original one, built 03/2018. The GE Transistor used is a russian MP20. Otherwise the same as above.
ReplyDeleteHi! First of all, i just recently discovered your magnificent page, thanks a lot for the schematics.
ReplyDeleteTwo questions: are there any alternatives to the TY-141P (they are not available in my country and very expensive to ship over) ? What does it do in the circuit?
What hfe should i go for the GE?
Thanks!
Is it possible to use 42TM-018 for transformer? It's a 10k/10k audio transformer, like the TY-141.
ReplyDeleteI would that would work then.
DeleteIn reference to the schematic linked at the top of this page:
ReplyDeleteThere was an conversation between Влад Чудак and Evan Goldsborough regarding C7 (1nF), R14 (5k6), and the GAIN pot (B25k). The schematic shows the sum of resistances (R14 + GAIN in series) across C7; the suggestion from Влад Чудак was that R14, GAIN, and C7 should all be in parallel. I'm not sure this was ever decisively resolved.
It makes quite a difference to the circuit:
If it's the summed resistances (as per schematic), then the resistance across C7 ranges from 5k6 at one end of the GAIN pot to 255.6k across C7 at the other end of the GAIN pot.
If it's the paralleled resistances (as per Влад Чудак), then the resistance across C7 ranges from 0 at one end of the GAIN pot to 5k47 at the other end of the GAIN pot.
Can anyone verify which is correct?
you are correct... there is a mistake in the layout right where you mentioned
DeleteIndeed there is this mistake in the layout
DeleteI tried it without transformers, it's realy working good, but sund very hard on a little gain. Today i've got transformers, sound - realy nice & soft. Q1 should have hfe more than 500, I used 2n5088 = 550, Q2 - mp 20, HFe = 69. CHip - 7660 = 24v. I made swith to get 9 & 24 volts, it's realy diferent soond. About 2 3pdt knobs - its very simple to do. 3pdt switch flick between two volume 25k pots. 3 pin potentiometers going through 3pdt to exit transformer. Find photo hudson electronics broadcast dual switch inside< & you will see it. https://imgur.com/55GF7bh
ReplyDeleteHas anyone drawn an actual schematic of this yet?
ReplyDeleteThanks
Ed
Like someone else has mentioned, the pin spacing for the transformer doesn't match. I bought the correct TY-141P, had to bend the legs in a few mm.
ReplyDeleteIs there a mistake at the pin 1 of the Gain pot? The negative side of the C6 cap should go where the R14 (5.6K) and the C7(1n) meet according to the schematic and it goes directly to the pin1 of the Gain pot in the layout... am I right about that?
ReplyDeleteYep. I built it and it worked fine at 9 volts but was garbage at 24 (extremely gated, and less than unity volume even when maxed out). Fixed my layout to match the schematic and it sprang to life.
DeleteCan I use a 600:600 ohm transformer for this?
ReplyDeleteI have 8x nice little 600:600 audio transformers, which I'd love to hear in this context, but I guess this may load the circuit too much?
Which 15v diodes is everyone using?
ReplyDeletesame question on the 15v diode? what did everyone use?
DeleteFigured it out. 5818 or 5819 would do, right?
DeleteWould 1/4w resistors be good enough if I wanna power this pedal with 18 or 24v? Or would I need bigger resistors?
ReplyDeleteThanks so much for all your work!
1/4 watt will be fine.
DeleteHi,
ReplyDeleteTalking about LT1054/max1044 replacement, as you describe in 1981 DRV project, the only thing to do (if you choose max1044 chip) is only connect pin 1 with pin 8. Looking the 1981 drv pcb, pin 5 of LT1054 is NOT connected, while the same pin on Broadcast project is grounded.
Since I only have max 1044 chip available, can I replace the chip without problems, or have I cut the trace of pin 5 grounded?.
Thank you very much
Can I use the 7760 in the same way of 1044? thx!
DeleteYou can leave pin 5 connected. I've seen voltage doubler schematics with the 1044/7660 where pin 5 is grounded and where it's not. The key thing is connecting pin 1 and 8. And yes you can use the 7660 in place of the 1044.
DeleteMany thanks for your answer and helping, very precious.
Deleteciao from Italy
Is there any suggestion about Hfe of BC549C and germanium OC71 transistor?
ReplyDeleteMany thanks
Has this layout been fixed concerning the 5.6k resistor (R14) and 1nF capacitor (C7) going to the gain pot?
ReplyDeleteHi, the layout is incorrect. The 100uf cap negative lead should not go to Gain 1, but to the junction of the 5.6k resistor and 1nf capacitor.
ReplyDeleteI can confirm Harleking Effects' comment : the 100uF (C6) cap is missplaced and should go to the junction of R14 (5.6k) and C7 (1nF) instead of Gain 1. This way the layout is correct and you don't have to change the position of the 5.6k and 1nF (referring to the comment of Evan Goldsborough).
ReplyDeleteI found my build to be really bright at first, but after checking and correcting the position of the 100uF cap, it now sounds really close to the original.