JBLoudG20 Posted June 8, 2007 Report Share Posted June 8, 2007 So what are you currently working on? Researching for your next wallet buster? I just ordered all the parts for a SOHA, and I am comtemplating a M^3. Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 8, 2007 Report Share Posted June 8, 2007 Ugh, you really want that list... ok, here goes. The Defintes (currently underway) 1. Balanced DAC of unmentionable origin with a sigma22 power supply operating at +/-12V, the DAC is done, the power supply isn't. 2. Sigma11 power supply for SB3 (for me, finally). 3. Sigma11 for SB3 (for a friend). 4. Sigma11 for Apogee MiniDAC (again, for a friend). 5. Hagerman Bugle - the board has been populated for 6 months and I just need to case it up. Some day, some day. The Maybes (some big maybe, some small maybe) 1. Balanced Beta22 - this is pending the outcome of the balanced DAC, if the DAC works as well as hoped this will quickly become a definite. 2. Aikido - I've had all the parts for this project for the past year almost and still haven't started it. Before I had too much going on, now I have the Wheatfield which quite frankly I'm not sure I ever want to part with so the Aikido once again gets shuffled to the back burner. It hurts my head bad to have $600 worth of parts sitting in a box gathering dust. 3. Further modification of the Wheatfield. I've mildly tweaked this amp already but if I can coax some more suggestions out of Pete I might have another go at it. Or I might make the great leap and try to PTP a new one. That's all I can think of now, although I'm sure there is stuff that I'm forgetting about. Quote Link to comment Share on other sites More sharing options...
aerius Posted June 8, 2007 Report Share Posted June 8, 2007 Currently I'm not working on anything, the weather's too nice outside and I'm too lazy to plug in my soldering iron. Recent projects have included the following: 1) Continued tweaking of my Objective-Interim tube amp, mostly playing around with new input tubes 2) A proof of concept parafeed amp using a 12SN7 and 12W6 in triode mode 3) A cRaptor based on KG's schematics just to see how bad it sounds (even powered it with a switchmode filament supply) 4) Various DC filament supplies, trying to make a super-simple super-quiet one As for what's next, these are all still in the thinking stages 1) A tube phono amp of some sort 2) A 2A3 headphone amp of some sort 3) A glowy nightlight using an 872 mercury vapour rectifier Quote Link to comment Share on other sites More sharing options...
mirumu Posted June 9, 2007 Report Share Posted June 9, 2007 I'm currently acquiring parts to build an electrostatic transformer box for driving Stax headphones off a power amp. I had a pair of custom transformers made to my specifications in England that can handle either a 1:25 step up ratio or a 1:50 ratio depending on the configuration. They're spec'd to have a flat response from 5Hz to 40Khz although there is a chance there may be some resonance in there despite the designer doing his best to minimise the possibility. Those are the risks you take with custom transformers. I had no size or weight requirements so each transformer weighs a little over 3KG (near 7lbs) and occupies about 13cm (5 inches) square in order to reach the audio specs I'd requested. I still have to build a bias circuit for it, I'm looking at implementing an always-on bias circuit that Kevin came up with. Funnily enough though I'm having trouble finding a simple isolation transformer with a 240V primary and secondary (New Zealand uses 240V). None of the local companies seem to stock any and the local manufacturers refuse to even talk to me as I'm not a registered tradesman so ironically it looks like I have to buy one from the US. Ah well, I've wanted a Digikey account for quite a while anyway... Once this project is out of the way I'm moving on to a tube amp but before that I want to pick up a transformer winding tool of some sort. Maybe a basic hand operated one or maybe something more fancy. I seem to be needing more and more of these things and I just don't have the eye for doing it right by hand. When I do move on to the tube amp, it will either be a dedicated electrostatic amp based around high voltage DHTs or a more conventional tube power amp (still DHT if I can). I do realise such things are very dangerous so I intend to be extremely paranoid when building such a thing and I'm leaning towards more traditional power amp option to start with. Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 11, 2007 Author Report Share Posted June 11, 2007 At the moment, I am designing a new delayed turn-on circuit. I like AMB's design for the epsilon 12, but I have my own gripes about it: 1. its relatively expensive: (read: I am a cheapass) 2. I do not like how if you do not have the values correctly chosen, the thing can turn off on you during listening (or that is how I have read it, I could be mistaken) The good things though: 1. Great headphone protection from turn on surges, and even DC offset. 2. Fantastic documentation (as is par with AMB) Why I want a new circuit: I ONLY want a timed delay. Something that will be used maintly for hybrid tube designs, to switch a relay after 30 or so seconds.(or a normal tube design, if the user is willing to build an extra PSU for it). I'm looking for it to just wait a specified time, then switch the relay and keep it on. It will not prevent any turn off-pop, but will wait for the tube to warm up sufficiently for the power on surge to go away. Also, I want it cheap. Like under $10 cheap. I have a hard time justifying a $50 time delay circuit for a $30 YAHA amp or a $50 SOHA, which is the main aim for this circuit. Also, it give me something fun to do and play with (which is also a big motivator here). At the moment, I have come up with a rough design using a 555 timer,4 resistors,2 caps, 1 7812 regulator, 1 diode, 1 2n2906 PNP transistor and a DPDT relay ( I do like the specs on the one AMP used, and I might use it, depending on the final cost). I'm going to see what I have on hand to prototype, an dhopefully be able to incorporate this into my upcoming SOHA build. Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 11, 2007 Report Share Posted June 11, 2007 Busy weekend... I also got the sigma22 built for my DAC which means that I might get to fire that up for the first time in a week or so... YIKES! Quote Link to comment Share on other sites More sharing options...
Salt Peanuts Posted June 11, 2007 Report Share Posted June 11, 2007 I'm currently working on whether or not to get into DIY or not. My heart says yes, and my wallet says no. LOL. Quote Link to comment Share on other sites More sharing options...
KenW Posted June 11, 2007 Report Share Posted June 11, 2007 By "project", I'm assuming it can be something other than electronic/DIY builds? Anyway, I just secured a room in the house for my own personal private space. Spent the past 4 days sanding/painting/steaming with the intent of making it a listening room. One more coat of paint on the trim and I'll be ready to make the move. Biggest problem is furnishing it.....specifically, a rack and some sort of storage case for all the CD's I own. I'll leave the seating to the wife....as long as it passes my fanny test, I'll be pretty happy with the esthetics. Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 11, 2007 Author Report Share Posted June 11, 2007 Sounds good! If we count non-audio stuff (or closely related to audio): I built one of these: http://www.staples.com/webapp/wcs/stores/servlet/StaplesProductDisplay?langId=-1&storeId=10001&prodCatType=2&catalogId=10051&productId=156235&cmArea=SEARCH yesterday for listening and lounging. Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 11, 2007 Report Share Posted June 11, 2007 By "project", I'm assuming it can be something other than electronic/DIY builds?If that's the case one of the my big summer projects is to build an extension off of my back deck. Space is a little tight now so I'm going to add 4' in one direction and 3' in the other. Should be able to bang that out in a couple days. My dad and I built a shed last summer when I found out that HD/Lowes wanted about 5 grand for what I could build for $1500. It has doors now, but that's pretty much it. Quote Link to comment Share on other sites More sharing options...
en480c4 Posted June 11, 2007 Report Share Posted June 11, 2007 Well, no audio-related projects, but Nate was a huge help in the wiring part of my current project... Saturday we installed the wiring harness for the whole thing in about 8 hours. Pics are the only way to do the project justice... Starting from last October through this weekend: I still have a few odds and ends to wrap up, but I'm hoping to have it back on the road in another week or two. Quote Link to comment Share on other sites More sharing options...
deepak Posted June 19, 2007 Report Share Posted June 19, 2007 I'm brushing up (and learning a lot of new stuff) for my DIY phono stage the Hagerman Bugle. I want to try my best to build this independently and it helps that I have a ton of free time. I've been thinking about getting into gas powered RC cars, they look hella fun but unsure about my living situation in the fall so going to hold off on that. Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 19, 2007 Author Report Share Posted June 19, 2007 I'm an idiot an dsoldered the TO220 packages for VR1 & VR2 in my SOHA backwards. They got hot real fast, and I instantly saw what I did. The +12 supply for the opamp portion was reading 13.5v when I tested it, and clearly something was wrong because that was supposed to be the output from the regulator (7812). So I flipped them around, and the voltages were still whack. 0v if the opamp was in place, 13.5 if it wasn't there. The negative rail (7912) was reading -9volts. oops. There was still output though, and 1.5v of DC offset, LOL. I ordered two more regulators, and they should arrive tomorrow. I also ordered all the parts that AMB stocks for my MMM, but that was the end of my headphone budget. It'll be a while before I order te rest of it. Also, a question for Nate: as you saw in the toehr thread, I plan on using some OPA637's I have for L & R. Think it will make a big difference if I use say a OPA132 (I think thats the single part number) or another cheaper opamp for the ground channel instead of a 627? I'd think there would be a tiny difference, but nothing major (or warranting another $20 that I'd rather put into a better PSU). Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 19, 2007 Report Share Posted June 19, 2007 Also, a question for Nate: as you saw in the other thread, I plan on using some OPA637's I have for L & R. Think it will make a big difference if I use say a OPA132 (I think thats the single part number) or another cheaper opamp for the ground channel instead of a 627? I'd think there would be a tiny difference, but nothing major (or warranting another $20 that I'd rather put into a better PSU). I'm certainly no authority on this as honestly I've never tried to roll ground channel opamps to see if there was a difference. Based on what I've read there is good motivation to use as good an opamp (if not better actually) in the ground channel. There are some interesting discussions on the three channel topology at Headwize if you're looking to learn more. In short, my advice, use the 627. If you don't have one post a WTB thread at Head-fi, you can usually pick one up for about 50% of retail without too much difficulty. Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 19, 2007 Author Report Share Posted June 19, 2007 I have read a lot of that stuff on head-wize, I just remain skeptical that the ground channel opamp can influence sound more than the stereo channels. I guess this is a good way to learn for myself. Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 20, 2007 Report Share Posted June 20, 2007 Well, with the sale of my single-ended Beta today I will be officially launching into balanced-beta land shortly. My wallet weeps. Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 20, 2007 Author Report Share Posted June 20, 2007 [me=JBLoudG20]is jealous.[/me] I guess that means your DAC was successful? Can you reveal your source yet? My $2 parts order with $10 shipping from Mouser should arrive today, and I can fix arguably the stupidest soldeirng mistake I have ever made. then with luck, my SOHA will be up and running. However, now I regret spending the $100 on the SOHA, when I could have used it to buy the rest of the parts I need for my M^3. I'm chomping at the bit to build it, but cannot afford the rest of the parts, lol. I should never have bought the parts from AMB, then I'd be fine, and not have the PCB sitting on my desk staring at me when I sleep. Quote Link to comment Share on other sites More sharing options...
Salt Peanuts Posted June 20, 2007 Report Share Posted June 20, 2007 Well, with the sale of my single-ended Beta today I will be officially launching into balanced-beta land shortly. My wallet weeps. Are you making a 4-channel or 6-channel one? Here's hoping I'll have my single-ended Beta22 and you'll have your balanced Beta22 completed before the next area meet - whenever that may be. Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 20, 2007 Report Share Posted June 20, 2007 [me=JBLoudG20]is jealous.[/me] I guess that means your DAC was successful? Can you reveal your source yet?The DAC is nearly done, and I'm taking a bit of a gamble selling the SE beta this early but the opportunity to sell the amp presented itself in my favorite way, that being that someone I'm friendly with was looking for one and the deal worked well for both of us. It won't be leaving the Headcase family. And until the DAC is up and running I'm going to keep mum on the source. By all reports it should be friggen killer. Are you making a 4-channel or 6-channel one?Six, since I'm clearly unbalanced as well. Here's hoping I'll have my single-ended Beta22 and you'll have your balanced Beta22 completed before the next area meet - whenever that may be. Yeah, my first beta was my quickest build ever from start to at least sort of completed. I'm hoping the same holds true for the balanced version but holy mother of pearl there are a lot of parts to solder... Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 21, 2007 Author Report Share Posted June 21, 2007 I completed my SOHA last night, which means the saving begins for MMM and a o11. Following that: mini^3 CK2III Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted June 29, 2007 Author Report Share Posted June 29, 2007 Started some sketches on a low voltage tube/hybrid amp. Similar to the YAHA, but with a mosfet buffer instead of an opamp. Quote Link to comment Share on other sites More sharing options...
n_maher Posted July 3, 2007 Report Share Posted July 3, 2007 Got one of the four power supplies I'm working on done last night... It's a sigma11 in a Hammond box but has a custom paint job. I'd never tried that before and decided I was sick of anodized finishes so I gave it a whirl. Came out more than decent, I think. More pics and info to come in the other DIY build thread. Quote Link to comment Share on other sites More sharing options...
JBLoudG20 Posted July 3, 2007 Author Report Share Posted July 3, 2007 Looks good! I'm more than likely going to be building one for my M^3 after I scratch my tube itch. I *should* clear enough cash tongight to order up the last of my M^3 parts. I will very likely tack on the parts to build my VanTOTL again. The cost of parts from Mouser is like $45 including a case. The expensive part is hoarding 6SN7 and 6AS7G tubes, and the transformer. Quote Link to comment Share on other sites More sharing options...
aerius Posted July 3, 2007 Report Share Posted July 3, 2007 I *should* clear enough cash tongight to order up the last of my M^3 parts. I will very likely tack on the parts to build my VanTOTL again. The cost of parts from Mouser is like $45 including a case. The expensive part is hoarding 6SN7 and 6AS7G tubes, and the transformer. The easy solution is to go with 12SN7's which are still a fair bit cheaper than the 6V version. A 25V version of the 6SN7 also exists but as far as I know the only variant available is the RCA grey glass one. There's also 12 & 25V versions of the 6080 (6081 & 6082) which as far as I know is a drop in substitute for the 6AS7, and usually a lot cheaper too. Quote Link to comment Share on other sites More sharing options...
Grand Enigma Posted July 3, 2007 Report Share Posted July 3, 2007 n_maher... wanna come finish up my Jeep for me? I have a 98 ZJ buggy awaiting some lockers Quote Link to comment Share on other sites More sharing options...
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