Passinwind

[quote name='umph' timestamp='1427155090' post='2726642'] what software do you use for making tests like these and doing sweeps? [/quote] [url="http://audio.rightmark.org/index_new.shtml"]http://audio.rightma...index_new.shtml[/url] [url="https://www.trueaudio.com/rta_abt1.htm"]https://www.trueaudio.com/rta_abt1.htm[/url] [url="http://www.holmacoustics.com/holmimpulse.php"]http://www.holmacous...holmimpulse.php[/url] [url="http://www.roomeqwizard.com/"]http://www.roomeqwizard.com/[/url] RMAA is a bit of a hassle if you need real-world calibrated results for signal to noise measurements, as sound cards are not very well standardized, and also because the software works best at pretty hot input and output levels that a lot of musical instrument gear will struggle with a bit. It's quite useful for DIY benchmarking even without jumping through all the hoops though.

[quote name='Chienmortbb' timestamp='1427146814' post='2726527'] The designs are early stage Charlie and I am the one that never goes to a blockbuster, and despite everyone's efforts never got Springsteen,so I will not use blue LEDs just because they are en vogue. Might try some purple ones though. It helps having you guys around though to keep me honest.Now where can I buy some HH electroluminescent strip. [/quote] Ha...nice! I sometimes use blue LEDs just because they tend to match my usual graphic schemes. I turn the brightness way down though, even on the low intensity highly diffused variants I have on hand. The front panel for my new preamp build is due in from Front Panel Express in a few days, and after laying out all that cash I have to say I'm rather envious of your option to take a few do-overs with little penalty.

[quote name='Chienmortbb' timestamp='1427043980' post='2725005'] I have mocked up three options for the front panel and would appreciate comments. [/quote] No blue LEDs? Beyond that, I'm going to sit back and enjoy this phase. I've made enough work for you as it is!

[quote name='sifi2112' timestamp='1426955768' post='2724004'] Cheers .. I did email Hypex but they haven't replied as yet. I can't really afford any of them anyway so when I build my next cab I think I might leave space to integrate the minima one unit I have in my powered bagend cab. [/quote] I looked into buying one of those at one time too. I ended up buying one from SpeakerPower because I wanted access to the DSP functions, but it's an OEM version and the price has since gone sky high on both that and the non-DSP consumer version.

[quote name='sifi2112' timestamp='1426856389' post='2722761'] I've built a few cabs & would love to build just a power amp into one but to be honest most of the amp techy stuff is way over my head. I looked at the module you bought but even tho they say its 'plug n play' I don't see it but it is new to me. [/quote] The closest thing to plug and play for an in-cab build is probably something like one of the plate amps from MiniDSP, Hypex, or SpeakerPower.

[quote name='plunkrock' timestamp='1426939558' post='2723683'] I have recently picked up a pre I really like and have been looking at ways to amplify it in a small package (I don't drive so if everything can fit in a gig bag that would be awesome) The Minnie D would be ideal but out of my price range at the moment, so looking at other Class D heads I can run into the effects loop on. I had an Orange TB500 before, I would prefer something flat but if that's the loudest option might pick up another. Anyone have any experience with this? Models I am considering: GK MB500, Ampeg PF500, Aguilar ToneHammer etc. [/quote] The Minnie 800 uses the same ICE power amp module as the TH500, the G-K 800 twins, the Genz 900-9.x amps, and the Kustom KXB500, among others. If the G-K MB500 is loud enough for you, there are plenty of other amps that use that (smaller) ICE module as well. In many cases there can be somewhat different mojo from the manufacturer-added buffer/preamp at the EFX return or power amp input, so how that works with your particular preamp may be a little hard to predict without direct experience. I've tried running a few of my DIY preamps into the GK MB Fusion 500 power section, that worked just fine without really adding much GK-ness. IMHO the new ICE 700 watt module sounds a bit nicer than any of these, and will run without a fan if that matters to you, but I'm not familiar with any moderate budget implementations just yet.

<p>[quote name='Chienmortbb' timestamp='1426691035' post='2720856'] I have enough space to do the pot/switch on either panel and the Decals are so thin that I can add the graphics to the rear later.[/quote] Being able to do the graphics in stages is a great reason to go with your method. I've done inkjet printing on sticky-backed plastic sheets a few times, but those decals look a lot nicer.

[quote name='Chienmortbb' timestamp='1426688085' post='2720796'] The graphics on the panel were designed on a computer and printed onto Waterslide Decal Paper. This works like the decals in an Airfix or Revell kit. [/quote] Looking really good. Are you going to have an EFX return pot and/or EFX bypass switch on the front panel?

[quote name='Bottle' timestamp='1426112296' post='2714668'] Oh, that's mighty purty [/quote] Thanks. It actually sounds pretty nice too, always a bit of a crapshoot when doing my own design. Here's the matching power amp: 700 watts @ 4 ohms, 7.5 pounds. The two modules will be able to fit side by side in a 19" rack once the new front panels get done, or can be stacked vertically for use with smaller cabs.

[quote name='JapanAxe' timestamp='1426078565' post='2714092'] Hmmm... The Trinity Trip Top chassis-only kit is $1600. [/quote] Huh? The link I posted says $670, plus $30 for a 50 HZ transformer core for those who might prefer that. Yes, there is a 234 volt primary. Is that link duff though?

[quote name='pfretrock' timestamp='1425772875' post='2710633'] Maybe get Barry onto the case.... [/quote] Yes, exactly.

Pardon me if I'm stretching the definition of effects a little bit. This is an in-progress pic of my current bass preamp/DI build: I'm just about to order the permanent front panel, which will look a lot like this, in blue anodized aluminium: There's a TalkBass build thread [url="http://www.talkbass.com/threads/a-diy-1-2-rack-bass-preamp.1135423/#post-16982343"]here[/url] as well, but I would be perfectly happy to discuss details in this thread if desired.

[quote name='pfretrock' timestamp='1425749990' post='2710364'] A bit expensive? Kit Price does not include tubes. Perhaps there is extra mojo in the transformers [/quote] [i]Buy once, cry once.[/i] But that high ticket was partially why I suggested pitching the general idea to someone more local to you guys, and maybe more in tune with the market there.

Here's a promising looking one based on the B-15: http://www.trinityamps.com/Product_Kits_Triptop.htm Maybe you can get your guy interested in doing something similar?

[quote name='Roland Rock' timestamp='1421918465' post='2666479'] Any detail on the power section? [/quote] A magazine reviewer I know mentioned that it uses one of the new ICEpower 700 series modules, which are reputedly a nice step up from the earlier versions. Edit: I now have a little experience with that module myself, it's a ripper.

[quote name='paul_5' timestamp='1425414549' post='2707143'] actually, if you were going to get inside it to mess about with the components then the most sensible suggestion would be to rip the 'Flash Burn' LED out and replace it with a sensible one... [/quote] That has worked well for me. I found some really nice low intensity diffused lens blue LEDs on eBay -- took a while to find them, but they do exist. I then run them well under the max current spec, and at that point they're no longer obnoxious at all, at least by my standards.

[quote name='jensenmann' timestamp='1425212546' post='2705058'] Thanks for the LT1169 info. I´ll give it a try. Some parameters do look promising. [/quote] It's a pretty nice sounding DIP-8 chip, LT1113 is decent too. Not the fastest or latest-greatest, but sometimes that can be a good thing.

[quote name='jensenmann' timestamp='1425153375' post='2704614'] . I´d say +1 to passinwind´s comments about TL072s and OPA2134s from that point of view. But in my experience with MI gear I´d propose to use TL072s because their artefacts make a certain sound which might help a signal to cut through on stage. HiFi sounds are not the easiest to handle thing for me on stage. [/quote] The Fender tone stack can get a bit lost due to all that inherent mid-scoop, for sure. I built up Rod Elliot's Project 27, which is a lot like how you've described yours. You might give the LT1169 a try if OPA 2134/2132 is too "gooey" for your taste, but you still want lower noise than the TL072 affords. I used Rod's bright switch circuit in mine, which cuts like crazy if desired. The Keutzer preamp's tone stack is a pretty standard Baxandall variant, which can be pretty hi-fi, but can also boost mids pretty effectively. In my own designs I sometimes like to mix the two, with active bass and mids in one section and a lossy passive treble control in another, later stage. All of this stuff depends a lot on playing context. I don't play fretted bass, ever, and rarely play much rock these days either. DIY builds can be great for really nailing things down for your own wants and needs, if you don't go crazy first!

[quote name='UglyDog' timestamp='1424794760' post='2700544'] Oh bum, I missed that Feel a bit of a twit for starting this thread now! That ½ rack pre of yours is gorgeous. [/quote] Thank you! Mr. Kreuzer passed away a few years ago, so I wonder if anyone is doing anything with the board layout he published, or has done an updated one? I'll look into that a bit.

I've not built one, but it looks pretty worthwhile and people I trust have told me it sounds good. Someone else posted about this last month: http://basschat.co.uk/topic/252766-kreuzer-bass-preamp/ Please keep us posted on how it goes. I always enjoy seeing how other people manage their DIY builds, and I'm just finishing up a [url="http://www.talkbass.com/threads/a-diy-1-2-rack-bass-preamp.1135423/"]new one of my own design[/url] at the moment, FWIW.

Stambaugh fretless: I've played it, sounds great.

[quote name='timmo' timestamp='1424528960' post='2697358'] I was just looking at the amps and cabs for sale and saw this. Just didn`t get what the function is, as i thought you would have an amp for all the functions. [url="http://basschat.co.uk/topic/253503-rare-gt-groove-tubes-bass-preamp-swr/"]http://basschat.co.u...ass-preamp-swr/[/url] [/quote] Quite a few of us use pro sound grade power amps in our bass rigs, for one reason because virtually no bass amps make enough power to satisfy some people. Since that power amp doesn't have tone controls and since it typically wants a higher level input signal than our basses provide, a standalone preamp like that becomes necessary. The often large-ish form factor also leaves lots of room for extended functions that are less often seen in integrated bass amps. Floor pedals tend to just provide another tonal flavor, and they can be very handy for getting "your sound" through someone else's rig as well.

[quote name='Chienmortbb' timestamp='1423657235' post='2687466'] So now to order some good parts and check out the latest circuit. [/quote] I just did a bit of benchmark testing in RMAA and saw a few subtle things that may need massaging, but it looks pretty good all in all. These figures are with both the high pass and the parametric EQ engaged, neither of which change the measurements all that much when bypassed.

[quote name='Passinwind' timestamp='1422986178' post='2679196'] Lookin' good, real progress going on. I'm on to final wiring of my set of preamp boards, hope to be up and running by week's end.[/quote] Done, and working pretty well for such early days. Should be safe to stuff those boards now Chienmort.

[quote name='lee650' timestamp='1423354769' post='2683959'] . I had a radial bassbone which dones not have high impedance inputs and it does not drove a power amp very well ( I struggled with my Berg IP, with the bassbone). [/quote] The new Bassbones do have a dedicated 10Meg piezo preamp now, but they are still unity gain pieces and as such are not meant to drive power amps.