trent900 Posted December 9, 2009 Share Posted December 9, 2009 Hi! Can anybody help with this problem? I've checked the wiki as is my duty - and a wonderful thing it is - but it doesn't seem to answer this question. Anyway. I would like to have a system where my snap, crackle and pop input stage in my GK amp is partnered with something a bit fatter, cleaner and more laid back - like an Ampeg SVP-pro. So I have conceived of a 'distribution board' which: [list] [*]Fits into a 19" rack [*]splits the signal from the bass to run through the two preamps parallel [*]recombines the signal post-preamp using a blend pot [*]sends the combined signal to a rack compressor and receives it back [*]sends the compressed signal to an FX loop and receives it back [*]fires the now horrifically mauled signal into the GK's power stage. [/list] Now I'm not much of a one for electronics. I do have talented friends who will help with circuit design, board layout and actual manufacture, but they're not audio people so they can't really help with component choice. I have found a nice signal splitter on Jensen transformers' site: [url="http://www.jensen-transformers.com/as/as014.pdf"]this splitter[/url]. I plan to fiddle with it to the tune of deleting the automatic power on/off mechanism that uses the two batteries and replace that with an always-on DC mains supply, probably 15V, and delete two of the output lines. This leaves the costly components as: [list] [*]A Burr-Brown (now Texas Instruments) OPA627 opamp [*]Two Jensen JT-11P-1 transformers [/list] I also plan to have switchable active and passive splitters, the passive of which requires [i]another[/i] JT-11P-1. Now here's my problem: those transformers are $70 each. The opamp will cost about £27 but I can cope with that. My question is: do I [i]have[/i] to use the Jensen transformers? I know they're meant to be the absolute dogs and I would like to make the splitter stage as transparent as possible but man, $210 plus shipping plus duty plus VAT doesn't half make me squeal for just 3 little components. Can anyone suggest an alternative? Does anyone have experience of doing something like this? If there's no sensible alternative then I will start to look at fulfilling the same requirement using a sequence of commercially-available boxes but I want to build it myself for the educational value, the satisfaction, and rack neatness. Many thanks in advance! Any other comments on the idea or proposed setup very welcome also. Jon Quote Link to comment Share on other sites More sharing options...
Lfalex v1.1 Posted December 12, 2009 Share Posted December 12, 2009 From messing around with various ideas on my own, I can safely say that my £80 8 track mixer does all but 2 of these, namely; It isn't rack-mountable. It only has one FX loop (and wouldn't be able to cope with the compressor requirement as stipulated) BUT it does allow a wet/dry FX mix for each channel. It has enough gain to enable me to use each channel as a pre-amp. I can mix in MP3s for practice purposes. And it will merrily drive a big pair of headphones! Oh, and it'll phantom power up to 4 devices via XLR I have 5 pre-amps at my disposal Ampeg SVP Pro Hartke VXL bass attack MXR M-80 Peavey MaxBass The desk channels themselves. Which is the best? Damn it, the desk channels are! clean as you want, but overdo the gain, and even (a good) mild overdrive is available! 3 band EQ, too! The SVP gives the grit, but can be too noisy. The Peavey has switchable/combinable SS and tube stages, but is hamstrung by poor tube gain, lack of a master output "volume" and noisy switching. The VXL is too clean but is very "Hi Fi" The MXR is okay. but sounds a bit dull, and the OD can't match the desk or SVP. At least it's switcahble, though. Check out rack-mountable mixers and microphone pre-amps. They may secretly harbour what you seek, in spite of their not being bass-specific... Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted December 12, 2009 Share Posted December 12, 2009 [quote name='Lfalex v1.1' post='682512' date='Dec 12 2009, 08:17 PM']The Peavey has switchable/combinable SS and tube stages, but is hamstrung by poor tube gain, lack of a master output "volume" and noisy switching.[/quote] If its the right max preamp, there is a gain mod: [quote]Peavey Max Modification for More Tube Gain ========================== Put a 22mfd @ 25wv capacitor (70320012) or equivalent in parallel with R224 (1.5K). Make sure the capacitor is installed with the negative side to ground. This will bypass the first tube stage's cathode resistor and increase gain quite a bit. -- <-- greenboy ---<<<<[/quote] [url="http://www.lowdownlowdown.com/greenboy/DL/Max/"]link for other bits of info.[/url] Curious for someone else to try it first. The switching on my max doesn't do anything but make the noise, nothing changes, need to get it looked at and might have the mod done too. Quote Link to comment Share on other sites More sharing options...
umph Posted December 12, 2009 Share Posted December 12, 2009 [quote name='trent900' post='679356' date='Dec 9 2009, 06:35 PM']Hi! Can anybody help with this problem? I've checked the wiki as is my duty - and a wonderful thing it is - but it doesn't seem to answer this question. Anyway. I would like to have a system where my snap, crackle and pop input stage in my GK amp is partnered with something a bit fatter, cleaner and more laid back - like an Ampeg SVP-pro. So I have conceived of a 'distribution board' which: [list] [*]Fits into a 19" rack [*]splits the signal from the bass to run through the two preamps parallel [*]recombines the signal post-preamp using a blend pot [*]sends the combined signal to a rack compressor and receives it back [*]sends the compressed signal to an FX loop and receives it back [*]fires the now horrifically mauled signal into the GK's power stage. [/list] Now I'm not much of a one for electronics. I do have talented friends who will help with circuit design, board layout and actual manufacture, but they're not audio people so they can't really help with component choice. I have found a nice signal splitter on Jensen transformers' site: [url="http://www.jensen-transformers.com/as/as014.pdf"]this splitter[/url]. I plan to fiddle with it to the tune of deleting the automatic power on/off mechanism that uses the two batteries and replace that with an always-on DC mains supply, probably 15V, and delete two of the output lines. This leaves the costly components as: [list] [*]A Burr-Brown (now Texas Instruments) OPA627 opamp [*]Two Jensen JT-11P-1 transformers [/list] I also plan to have switchable active and passive splitters, the passive of which requires [i]another[/i] JT-11P-1. Now here's my problem: those transformers are $70 each. The opamp will cost about £27 but I can cope with that. My question is: do I [i]have[/i] to use the Jensen transformers? I know they're meant to be the absolute dogs and I would like to make the splitter stage as transparent as possible but man, $210 plus shipping plus duty plus VAT doesn't half make me squeal for just 3 little components. Can anyone suggest an alternative? Does anyone have experience of doing something like this? If there's no sensible alternative then I will start to look at fulfilling the same requirement using a sequence of commercially-available boxes but I want to build it myself for the educational value, the satisfaction, and rack neatness. Many thanks in advance! Any other comments on the idea or proposed setup very welcome also. Jon[/quote] you'll probably get away with just buffering the signal to prevent signal loss on the splitter, using the jensen transformers is a bit overkill but would get the job done perfectly. A blend between the two preamps would be easy to assemble and a buffered effects loop is also very simple, you shouldn't have a hard time sticking this all in a rack case aswell. This should be a good project if i was you i'd be tempted to do this all valve! Quote Link to comment Share on other sites More sharing options...
trent900 Posted December 14, 2009 Author Share Posted December 14, 2009 This is all brilliant, thank you guys. I suppose I've got a choice. Build something myself for about £160 and get exactly what I want, or just buy this: [url="http://www.altoproaudio.com/index.php?template=3&id_prod=28&id_padre=122123629051816"]Altolink[/url] I suspect it will come down to the state of the bank balance post new year! The altolink is obviously the sensible option! Thanks again guys. Jon PS. Lfalex, if you ever want rid of your SVP let me know... Quote Link to comment Share on other sites More sharing options...
ogri Posted December 20, 2009 Share Posted December 20, 2009 buddy, i ran two amps for a while an after trying various expensive solutions bought a second hand roland gp8 guitar effects processor with pedal board(about a grand new back when it came out in the eighties!)for a hundred quid off me local shop and just used it as an active signal divider. worked brilliantly, and was good fun messing about with the effects when there was nothing on the telly..:-) when i sold it got me 100 sovs back too... [quote name='trent900' post='684357' date='Dec 14 2009, 07:33 PM']This is all brilliant, thank you guys. I suppose I've got a choice. Build something myself for about £160 and get exactly what I want, or just buy this: [url="http://www.altoproaudio.com/index.php?template=3&id_prod=28&id_padre=122123629051816"]Altolink[/url] I suspect it will come down to the state of the bank balance post new year! The altolink is obviously the sensible option! Thanks again guys. Jon PS. Lfalex, if you ever want rid of your SVP let me know...[/quote] Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.