tag:blogger.com,1999:blog-3033460626772757790.post7887723425192716116..comments2024-03-25T18:41:36.946+00:00Comments on Paul In The Lab: Sparky 5 Watt Amplifier Stripboard Veroboard LayoutDrStevensonhttp://www.blogger.com/profile/13901235832359203061noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-3033460626772757790.post-27422239012424487672023-11-02T15:47:21.808+00:002023-11-02T15:47:21.808+00:00Thanks for posting this. I think I'm going to...Thanks for posting this. I think I'm going to try something like this for my homemade combo amp.kwkhttps://www.blogger.com/profile/05242796866127438724noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-16448225209614078912021-12-22T14:59:43.652+00:002021-12-22T14:59:43.652+00:00Great Project ! It sounds really good, and LOUD.
p...Great Project ! It sounds really good, and LOUD.<br />powered it with 2 9v batteries.<br />I changed the 220K resistor on the 741. It was way too much gain for me. Other than that, it's perfect, thanks ! Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-45606186592697644342020-08-05T01:20:29.646+01:002020-08-05T01:20:29.646+01:00What resistance speakers should be used with this?...What resistance speakers should be used with this?Old Reliable Musichttps://www.blogger.com/profile/04652409969197254388noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-60476038633314192112016-09-16T01:35:13.932+01:002016-09-16T01:35:13.932+01:00Built this amp a while ago, but I ditched the diod...Built this amp a while ago, but I ditched the diodes since I do not like hard diode clipping, and wanted it to sound a bit cleaner at higher volumes.<br />I also replaced R5 with a 250K pot in order to get a Gain pot, and I found my sweet spot about 1/4th the way up on the pot.<br />Now it breaks up with a nice crunch/overdrive when pushing the volume, and it stays quite clean until you get the volume past 2'o clock.<br />It now also handles pedals much better and has become a perfect living-room amp for my purpose.<br />Sounds great with my 10" Celestion Vintage 30 speaker mounted in an old reel-to-reel cabinet from the 60's.<br /><br />As for power, I use a 12v Moped Battery (I live off-grid) that last me about a week with active playing before I have to recharge it.<br />Brilliant!!!<br /><br />Thanks for all your efforts and contributions.<br />Looking forward to your MK.II version...Neil mcNastyhttps://www.blogger.com/profile/09931495437396592838noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-71095109486220238062014-08-11T10:04:22.019+01:002014-08-11T10:04:22.019+01:00What do you think of using two germanium 1N34A? Wo...What do you think of using two germanium 1N34A? Would it be better?<br />Greetings, thanks.Miguelhttps://www.blogger.com/profile/14075230674770526708noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-1090004693174337432013-08-31T10:36:20.031+01:002013-08-31T10:36:20.031+01:00I would say - try it out and see what happens I would say - try it out and see what happens DrStevensonhttps://www.blogger.com/profile/13901235832359203061noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-22012656502447566692013-08-31T07:24:39.226+01:002013-08-31T07:24:39.226+01:00is there any reason why back to back diodes on the...is there any reason why back to back diodes on the feedback loop of the 741 wouldn't work to give some OD?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-78749198101774479472013-07-31T16:28:45.489+01:002013-07-31T16:28:45.489+01:00Great, because that is what I had in stock, except...Great, because that is what I had in stock, except some 3300 /35 and 6800 /35 caps which might be overkill...Anonymoushttps://www.blogger.com/profile/00902255528997769480noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-35905890474674206892013-07-31T13:42:39.869+01:002013-07-31T13:42:39.869+01:00nothing really - I just chose an arbitrary high va...nothing really - I just chose an arbitrary high value capacitor for that bitAnonymoushttps://www.blogger.com/profile/11635505362975722538noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-81560663091010237592013-07-31T13:33:12.474+01:002013-07-31T13:33:12.474+01:00Hi, what happens if I use a 560 uF cap instead of ...Hi, what happens if I use a 560 uF cap instead of the smaller 470 uF cap at the output?<br />sincerely, <br />OlleAnonymoushttps://www.blogger.com/profile/00902255528997769480noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-90908476608357753972013-03-14T13:37:55.810+00:002013-03-14T13:37:55.810+00:00the 2.7 ohm resistor is for stability and stop it ...the 2.7 ohm resistor is for stability and stop it oscillating - or at least help it not to.<br />if you have 4 10ohm resistors - put them in parallel (make them into a resistor canoe) this will give you 2.5 ohms which will be better<br /><br />a charge pump won't work with it because it can't source enough current to run the LM384 - I can't remember what it draws off hand but it's a lot more than 100mA that you typically get from a MAX1044 or a 7660/1054 <br /><br />the higher the voltage - the louder you will be able to get it before it distorts. <br />it doesn't do well with overdrive pedals cause it doesn't have a proper preamp - that's why the english channel does sound good because that is a preamp of sorts.<br /><br />I have been working on a MKII of this with a decent front end but progress is slow cause I feel like crap haha. <br /><br />also there is a very similar amp project that doesn't have the problems you're having called the "Tonesucker" elsewhere on my pageDrStevensonhttps://www.blogger.com/profile/13901235832359203061noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-3213793907342792262013-03-14T12:27:25.480+00:002013-03-14T12:27:25.480+00:00Hi Paul
I built this one, it sounds good at low le...Hi Paul<br />I built this one, it sounds good at low levels but it quickly goes into crappy gated sounding distortion and even oscillation. I omitted the pot and put a 220 ohm resistor between VR1/VR2 and a 18K resistor between VR2/VR3. That makes the level fixed at a nice sounding "sweetspot". It's just alittle bit distorted but sounds nice. Insted I added a "pre-gain" pot going into the circuit to control the volume.<br /><br />I didn't have a 2,7R resistor though, so I tried a 10R (sounded bad) and a link insted (sounds better). What is the purpose of the 2.7R?<br /><br />I'm running it at 9v now, will 12 or 18 volts make alot of differance? It would be nice if it could be alittle louder at this semi-clean setting I've got... I've tried with a charge pump but that didn't work. Made the Sparky sound gated/starved...<br /><br />However, the circuit doesn't play well with other stomp-boxes. I've tried a few and most are turning the amp into oscillation and crazy noise. Even my Hermida Zendrive that loves to be stacked had the same problem running into the Sparky. Exceptions were my Catalinbread DLS (with a charge pump) and Runoffgroove English Channel which works fine going into the Sparky.<br /><br />Any way to solve this issue? I would love to built a stompbox circuit into the front-end.<br />BTW, I've got a good 600ma power supply.<br /><br />Cheers<br />/ FredrikFredrik Lyxzénhttps://www.blogger.com/profile/11088877879439472490noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-54971022438969711932013-03-03T22:29:04.552+00:002013-03-03T22:29:04.552+00:00I will do when I get time to, I'm currently wo...I will do when I get time to, I'm currently working on the MKII version so all of everything is plugged into that and various breadboards - the new one has a bass / treble EQ <br />DrStevensonhttps://www.blogger.com/profile/13901235832359203061noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-81398344429499613502013-03-03T22:19:17.137+00:002013-03-03T22:19:17.137+00:00Would you please record a clip in which you show u...Would you please record a clip in which you show us how dirty it gradually becomes ?Andrewhttps://www.blogger.com/profile/02489516210299648114noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-72306567429642370552013-02-23T00:17:41.686+00:002013-02-23T00:17:41.686+00:00I actually designed it around the TL071 but I then...I actually designed it around the TL071 but I then realized I had none so I used a 741 cause I have lots of them<br />and the LM384 is only $2 ish so all in all this is a very cheap amp considering the sound it gives youDrStevensonhttps://www.blogger.com/profile/13901235832359203061noreply@blogger.comtag:blogger.com,1999:blog-3033460626772757790.post-25977942633012353152013-02-22T23:34:14.637+00:002013-02-22T23:34:14.637+00:00paul, any reason you chose a 741 for the front end...paul, any reason you chose a 741 for the front end?<br />just curious, nice to see a normal chip being used instead of some expensive piece of twat.pinksterhttps://www.blogger.com/profile/13385798043782856976noreply@blogger.com