LukeFRC Posted July 6, 2023 Share Posted July 6, 2023 I have NO IDEA what it actually sounds like - but I want to make one https://aionfx.com/project/l4-bass-preamp/ ( @disssa has probably made one!) 1 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 6, 2023 Share Posted July 6, 2023 And no idea why Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 6, 2023 Share Posted July 6, 2023 21 minutes ago, LukeFRC said: I have NO IDEA what it actually sounds like - but I want to make one https://aionfx.com/project/l4-bass-preamp/ ( @disssa has probably made one!) Weird that it has a distortion but no way to control its gain/level? Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 6, 2023 Share Posted July 6, 2023 It has a gain per channel then a master out on the top right? Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 6, 2023 Share Posted July 6, 2023 35 minutes ago, LukeFRC said: It has a gain per channel then a master out on the top right? Ah this might be that Quote Link to comment Share on other sites More sharing options...
bloke_zero Posted July 7, 2023 Share Posted July 7, 2023 15 hours ago, LukeFRC said: I have NO IDEA what it actually sounds like - but I want to make one https://aionfx.com/project/l4-bass-preamp/ Bob Moog and Dan Pearce designed. Might be worth checking some youtube for the sound. FWIW I have a mate who had a lab amp back in the day (I think BB King had one or something?) and wasn't enamoured. But what would he know? He's a guitarist! Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 7, 2023 Share Posted July 7, 2023 I wonder what's the distortion source is. Is it Q3 and Q4 or is the transconductance amp IC8B is somehow overloading? I'm not that familiar with the transconductance stuff to see it from the schematics directly. Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 7, 2023 Share Posted July 7, 2023 The trimmer is to set IC8b to a certain gain for a given input - my guess is it’s to set a level for the transistors overdriving - but that’s just a guess. it’s not really taking me out of thing and make something else like a two channel fet2b and ROG ginger or something Quote Link to comment Share on other sites More sharing options...
BigRedX Posted July 7, 2023 Share Posted July 7, 2023 19 hours ago, LukeFRC said: I have NO IDEA what it actually sounds like - but I want to make one https://aionfx.com/project/l4-bass-preamp/ ( @disssa has probably made one!) Do you have an RD bass to put through it? Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 7, 2023 Share Posted July 7, 2023 20 minutes ago, BigRedX said: Do you have an RD bass to put through it? 20 minutes ago, BigRedX said: Do you have an RD bass to put through it? No, if they only work with Moog onboard preamps I'm fine, phew. Thanks for saving me! Quote Link to comment Share on other sites More sharing options...
tauzero Posted July 7, 2023 Share Posted July 7, 2023 4 hours ago, LukeFRC said: The trimmer is to set IC8b to a certain gain for a given input - my guess is it’s to set a level for the transistors overdriving - but that’s just a guess. it’s not really taking me out of thing and make something else like a two channel fet2b and ROG ginger or something There's more info in https://aionfx.com/app/files/docs/l4_bass_preamp_documentation.pdf Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 7, 2023 Share Posted July 7, 2023 2 hours ago, tauzero said: There's more info in https://aionfx.com/app/files/docs/l4_bass_preamp_documentation.pdf They don’t really explain the design choices Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 7, 2023 Share Posted July 7, 2023 1 hour ago, Badscrew said: They don’t really explain the design choices I guess they don’t have Bob Moog or his old team from the 70s on speed dial…. Aeon isn’t a bass player either so channel one is kinda fender like, and channel 2 is “different” Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 10, 2023 Share Posted July 10, 2023 Oh balls - I know I’m going to be pricing the parts up this week. Either a good idea or a bad!! Quote Link to comment Share on other sites More sharing options...
tauzero Posted July 10, 2023 Share Posted July 10, 2023 12 minutes ago, LukeFRC said: Oh balls - I know I’m going to be pricing the parts up this week. Either a good idea or a bad!! I shall await your verdict with interest. One minor point - I'm not sure if the documentation is wrong or the control is backwards, but it says the Mid control on channel 2 is counterclockwise for boost and clockwise for cut. Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 10, 2023 Share Posted July 10, 2023 2 hours ago, tauzero said: I shall await your verdict with interest. One minor point - I'm not sure if the documentation is wrong or the control is backwards, but it says the Mid control on channel 2 is counterclockwise for boost and clockwise for cut. That might be because it’s difficult to source reverse log pots. Did they use a normal log putting it backwards instead? This allows for a useful taper with a much more easy to find pot… Quote Link to comment Share on other sites More sharing options...
tauzero Posted July 10, 2023 Share Posted July 10, 2023 10 minutes ago, Badscrew said: That might be because it’s difficult to source reverse log pots. Did they use a normal log putting it backwards instead? This allows for a useful taper with a much more easy to find pot… No, it's linear taper. Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 10, 2023 Share Posted July 10, 2023 (edited) 4 hours ago, tauzero said: No, it's linear taper. Then it's weird. Easy to flip two wires if the action is backwards Edited July 10, 2023 by Badscrew Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 10, 2023 Share Posted July 10, 2023 5 minutes ago, Badscrew said: Then it's weird. Easy to flip two wires if the action is backwards Wired directly to board though Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 10, 2023 Share Posted July 10, 2023 24 minutes ago, LukeFRC said: Wired directly to board though Ouch. Then if it's indeed backwards, this means a screwup from whomever routed the board. Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 10, 2023 Share Posted July 10, 2023 (edited) 21 minutes ago, Badscrew said: Ouch. Then if it's indeed backwards, this means a screwup from whomever routed the board. I mean it's @tauzero that spotted it - with my limited electronics expertise I don't understnad that bit of the circuit and I'm not even sure how he could tell! (edit though it's the same on the schematic as the older L5 preamp they have been selling for years) Edited July 10, 2023 by LukeFRC Quote Link to comment Share on other sites More sharing options...
Badscrew Posted July 10, 2023 Share Posted July 10, 2023 As it was already suggested, might just be the documentation that's describing it wrong Quote Link to comment Share on other sites More sharing options...
tauzero Posted July 10, 2023 Share Posted July 10, 2023 I wasn't going by the circuit but by https://aionfx.com/app/files/docs/l4_bass_preamp_documentation.pdf - page 3 is about the controls. I was actually looking for information on the distortion. 1 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 10, 2023 Share Posted July 10, 2023 so one of the things I dislike about DIY is that a resistor issue cheap if I need lots, but mounts up if I only need a few of a given value, and the more likely a company is to have all the parts I need, the bigger volumes I need to buy. I switched with the last few projects from Musikding to CPC and Farnell and another one I forget the name of... So the rough cost of all the parts from CPC, Mouser and Musikding is coming too was about £80 - excluding knobs or PCB. Probably that would come down once I switched the CPC stuff to Mouser (I started on CPC, it was fine till I got to diodes and IC) and also when I crossed off any bits I already had The expensive thing, other than the case, is the £12.50 TEC 3-0923 power converter - from 9v to +-15v - given my cioks can do +15v there would be cheaper ways of getting a -15v from that but not without headaches. not a cheap project Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted July 10, 2023 Share Posted July 10, 2023 using the Mouser BOM thing it was also £80 Quote Link to comment Share on other sites More sharing options...
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