umph Posted January 30, 2012 Share Posted January 30, 2012 (edited) Right as some of you may know i'm a total amp nerd and i've been planning to start building amps etc. for a long time now. Basically been putting off finalizing things though because i've never been quite happy with the design and i've yet to think of a good name and design a logo for it. Think i've got to a stage where i'm happy with the design though! Specs so far on the head. Low / high gain inputs (read active / passive) 5 controls (depth / gain / bass / treble / master) Depth controls the bass roll off frequency - great for tightening things up Gain control is spread over 2 gain stages, making it pretty easy to dail in just the right amount of grind. Preamp heaters ran off seperate 12.6v dc supply, to keep things low noise. Speakon outs for 4 / 8 / 16 ohms. 600 ohm balanced, post OT transformer balanced line out (subject to tweaking till i find what sounds best) Running this one with a pair of kt88's in tetrode mode so it should be good for 100 - 120 watts. Totally over speced power supply, to avoid sag and keep the massive low end. Transformers hand wound in nottingham to HIFI quality. There are probably some things i've left out so feel free to ask me. Here are some shots of the very slow progress, although you can expect to see more happening soon! chassis lay out before drilling. everything drilled and fixed in. start of wiring, looks bit of a mess atm but should be alot better once everythings tidied up! Edited January 30, 2012 by umph Quote Link to comment Share on other sites More sharing options...
umph Posted January 30, 2012 Author Share Posted January 30, 2012 Also heres a picture of the final prototype in a roost case, on top of my cabs of doom for good measure! [IMG]http://i17.photobucket.com/albums/b96/stubbyrulz/DSC_0007.jpg[/IMG] Quote Link to comment Share on other sites More sharing options...
EBS_freak Posted January 30, 2012 Share Posted January 30, 2012 A beaut in the making! Quote Link to comment Share on other sites More sharing options...
Pentode Posted January 30, 2012 Share Posted January 30, 2012 That's looking very promising. Gotta love that iron! How about calling it the 'Hernia 100'? Quote Link to comment Share on other sites More sharing options...
paulflan0151 Posted January 30, 2012 Share Posted January 30, 2012 love to hear this, any ideas on pricing yet? Or are you at that stage? Quote Link to comment Share on other sites More sharing options...
GarethFlatlands Posted January 30, 2012 Share Posted January 30, 2012 Awesome, looking forward to hearing it this Friday assuming you're gigging it? Quote Link to comment Share on other sites More sharing options...
umph Posted January 30, 2012 Author Share Posted January 30, 2012 (edited) [quote name='Pentode' timestamp='1327961305' post='1519686'] That's looking very promising. Gotta love that iron! How about calling it the 'Hernia 100'? [/quote] Haha, it's not that heavy, it's still an easy one handed lift at this stage. The iron is awesome though, flat down to 20Hz, which is pretty brutal. No idea about pricing yet, i'll have to work it out after i've found someone who can do me faceplates / enclosures. Edit, yeah the roost is coming down with me on friday for some doom. Edited January 30, 2012 by umph Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted January 30, 2012 Share Posted January 30, 2012 Looks well thought out! I'm curious about the tone stack - is it based on a James/Baxandall type or something else? Quote Link to comment Share on other sites More sharing options...
umph Posted January 30, 2012 Author Share Posted January 30, 2012 [quote name='Beer of the Bass' timestamp='1327965020' post='1519781'] Looks well thought out! I'm curious about the tone stack - is it based on a James/Baxandall type or something else? [/quote] tis the james stack centred around 600Hz. i may still change it for an active bax though Quote Link to comment Share on other sites More sharing options...
GarethFlatlands Posted January 31, 2012 Share Posted January 31, 2012 Name wise, how about "Noisy 'un"? Quote Link to comment Share on other sites More sharing options...
MarkG3 Posted January 31, 2012 Share Posted January 31, 2012 Is looking good, have you taken this out of another amp or put bits and pieces together? Either way it looks good. How did you get the depth to work in terms of selecting the frequency? Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted January 31, 2012 Share Posted January 31, 2012 Aren't the laminations in the transformers traditionally mounted at 90 degrees to each other? I'm sure I've seen it/read it somewhere. I think it's meant to cut down mutually induced hum. Or something. I may have just dreamt it though... Quote Link to comment Share on other sites More sharing options...
Wil Posted February 1, 2012 Share Posted February 1, 2012 Looks fantastic, this will be an interesting thread! Quote Link to comment Share on other sites More sharing options...
rapscallion Posted February 1, 2012 Share Posted February 1, 2012 Tube Beast seems fitting... Quote Link to comment Share on other sites More sharing options...
charic Posted February 1, 2012 Share Posted February 1, 2012 Looks awesome! How about a play on your username and call it the "oomph" Quote Link to comment Share on other sites More sharing options...
BILL POSTERS Posted February 1, 2012 Share Posted February 1, 2012 [quote name='MoonBassAlpha' timestamp='1328052370' post='1521214'] Aren't the laminations in the transformers traditionally mounted at 90 degrees to each other? I'm sure I've seen it/read it somewhere. I think it's meant to cut down mutually induced hum. Or something. I may have just dreamt it though... [/quote] No your right. I was taught that as well. Dunno how much difference it makes in practice, but of the top of my head I cant think olf any commercial amps that didnt do it. Usually with the Choke at 90 degrees to the trannies as well. Looks nice though. Quote Link to comment Share on other sites More sharing options...
discreet Posted February 1, 2012 Share Posted February 1, 2012 Quote Link to comment Share on other sites More sharing options...
SebCarr Posted February 1, 2012 Share Posted February 1, 2012 Cool project. Valve rectifier? What pream tubes? Why 12.6v heaters? Some serious voltages to get KT88s singing. ~600v on the plates? Eek! Quote Link to comment Share on other sites More sharing options...
umph Posted February 1, 2012 Author Share Posted February 1, 2012 [quote name='S9_S12_Bass' timestamp='1328043167' post='1520912'] Is looking good, have you taken this out of another amp or put bits and pieces together? Either way it looks good. How did you get the depth to work in terms of selecting the frequency? [/quote] nah it's all parts i've got lying around. Depth control is just an rc filter so wasn't to hard to work out. Simple but effective. Quote Link to comment Share on other sites More sharing options...
umph Posted February 1, 2012 Author Share Posted February 1, 2012 [quote name='SebCarr' timestamp='1328092320' post='1521545'] Cool project. Valve rectifier? What pream tubes? Why 12.6v heaters? Some serious voltages to get KT88s singing. ~600v on the plates? Eek! [/quote] Nah keeping it SS The extra bases are there if i fancy turning it into a 200W. 12.6v heaters use half the current and thus produce less noise, although it doesn't make to much difference with dc. in regards to transformers, theres enough seperation for it not to cause an issue, only really matters if you have them right next to each other. Having one facing the other direction would mean more noise due to the magnetic field messing with the valves. Quote Link to comment Share on other sites More sharing options...
SebCarr Posted February 1, 2012 Share Posted February 1, 2012 SS rectifier makes sense if you're going for no sag. 12.6v shouldn't make any difference with DC if it's properly regulated and filtered, but can't hurt I guess as a little ripple will probably creep through. Quote Link to comment Share on other sites More sharing options...
umph Posted February 1, 2012 Author Share Posted February 1, 2012 [quote name='SebCarr' timestamp='1328097200' post='1521649'] SS rectifier makes sense if you're going for no sag. 12.6v shouldn't make any difference with DC if it's properly regulated and filtered, but can't hurt I guess as a little ripple will probably creep through. [/quote] Yeah the preamp heaters are all in series so it's easier to run them at 12.6v to. Quote Link to comment Share on other sites More sharing options...
BILL POSTERS Posted February 1, 2012 Share Posted February 1, 2012 [quote name='umph' timestamp='1328095047' post='1521607'] Nah keeping it SS The extra bases are there if i fancy turning it into a 200W. 12.6v heaters use half the current and thus produce less noise, although it doesn't make to much difference with dc. in regards to transformers, theres enough seperation for it not to cause an issue, only really matters if you have them right next to each other. Having one facing the other direction would mean more noise due to the magnetic field messing with the valves. [/quote] Bit unconventional having trannies at opposite ends, used to seeing them close and the signal path going from one end of the chassis to the other. Still, whatever works for you. Looks a nice job . Were the transformers and chassis easy to come across ? I've never seen any advertised anywhere. Quote Link to comment Share on other sites More sharing options...
umph Posted February 1, 2012 Author Share Posted February 1, 2012 [quote name='BRANCINI' timestamp='1328121017' post='1522205'] Bit unconventional having trannies at opposite ends, used to seeing them close and the signal path going from one end of the chassis to the other. Still, whatever works for you. Looks a nice job . Were the transformers and chassis easy to come across ? I've never seen any advertised anywhere. [/quote] Look at an amp thats not a marshall or a fender, they're pretty much all laid out like how i've got it. Chassis was ebay and i drilled it all out myself and transformers were from a chap i know Quote Link to comment Share on other sites More sharing options...
pantherairsoft Posted February 2, 2012 Share Posted February 2, 2012 This is looking very impressive. Some real thought and design gone into this! Quote Link to comment Share on other sites More sharing options...
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