mwhouston Posted November 9, 2015 Posted November 9, 2015 Hi Total spend isn't yet available but will be significantly less than that. With the $ the way it is, the spend on drivers alone now would be about $700. I had a few bits on hand such as the crossover PCBs, and a family contact is doing the cabinets. One quote for just the cabinets - and few people are interested in doing cabinets - was $1,200 pr. Happy listening Don, the guy who does my tube amp bases also does my cabinets. His work is excellent and charges fare.
betocool Posted November 12, 2015 Posted November 12, 2015 Re wiring and changing some boards on my guitar amp. Good progress today! 1
mwhouston Posted November 12, 2015 Posted November 12, 2015 Re wiring and changing some boards on my guitar amp. Good progress today! IMG_20151112_134643.jpg I thought the electronics goes in the chassis not on it. Are you still bread boarding?
Guest Muon Posted November 12, 2015 Posted November 12, 2015 (edited) Hehehe...that's funny ^^^^ Looks like he is just working out layout in that pic. Edit: But now I look at it I'm confused too Edited November 12, 2015 by ortofun
mwhouston Posted November 12, 2015 Posted November 12, 2015 (edited) Not a good image but you'll get the idea. This is an EL84 SE UL amp based on the Decware schematic for their triode power amp. I could have made this a triode amp by strapping grid two but the Edcor OPTs (under the bonnet) have the UL tap and these tubes are little pentodes plus every SE UL power amp I have built has really sounded excellent. If I wasn't so lazy I could put in a pentode, triode switch and have the best of both worlds. Still possible. The amp is assembled but not wired. That's next. Every time I build a tube amp I forget how many dozens hours of my live just vanish. Still going. I missed the order of some components but that's fixed. Here's the klanger: I have two Audio Note, Tin foil, Mylar and oil caps over from my recent MC build. I didn't think I could sqish them In but now I've done it.This amp is not finished but up for sale. PM me if interested. The guy I was exclusively building it for has changed his mind. Too late to stop. Too many tube amps. One must go. Edited November 12, 2015 by mwhouston
betocool Posted November 13, 2015 Posted November 13, 2015 I thought the electronics goes in the chassis not on it. Are you still bread boarding? No, not bread boarding, it's going to stay like that. Mind you, the metal chassis goes into a wood head, so, you'll be able to see the controls only at the front. Thing is, caps and the power amp with the heatsink were too big for the inside of the chassis. And last week or so I let the magic smoke of the power regulator go out. In the end, it was better to take it apart again, simplify the power supply, (the two big blue caps) add a second trannie for low voltage (12V, small one on the back left + small caps) and a new power amp board (right). There's a small pre at the signal input, and there's a DSP board between input and output which lets me add a few effects. Only way to fit all in, use top and bottom! And the easiest way to hook up all together was using the terminal boards. So yeah, it looks a bit prototype, but it's coming along real well. 1
mwhouston Posted November 13, 2015 Posted November 13, 2015 No, not bread boarding, it's going to stay like that. Mind you, the metal chassis goes into a wood head, so, you'll be able to see the controls only at the front. Thing is, caps and the power amp with the heatsink were too big for the inside of the chassis. And last week or so I let the magic smoke of the power regulator go out. In the end, it was better to take it apart again, simplify the power supply, (the two big blue caps) add a second trannie for low voltage (12V, small one on the back left + small caps) and a new power amp board (right). There's a small pre at the signal input, and there's a DSP board between input and output which lets me add a few effects. Only way to fit all in, use top and bottom! And the easiest way to hook up all together was using the terminal boards. So yeah, it looks a bit prototype, but it's coming along real well. Sometimes it is easier to split PS and amp on two chassis.
betocool Posted November 13, 2015 Posted November 13, 2015 Sometimes it is easier to split PS and amp on two chassis. Agree... if it's hifi. I've yet to see a guitar amp with a separate power supply. Happy to be proven wrong though!
davewantsmoore Posted November 13, 2015 Posted November 13, 2015 Agree... if it's hifi. I've yet to see a guitar amp with a separate power supply. Happy to be proven wrong though! The trick is define "guitar amp" .... here's Tubelab testing his 833A monster. 1500VDC is frightening stuff..... but putting it through that yellow clip lead?! <madness> 3
Guest Posted November 13, 2015 Posted November 13, 2015 Hello, is the acrylic screen there so as the 1500v cannot jump out and hit the guitar !??
davewantsmoore Posted November 13, 2015 Posted November 13, 2015 Hello, is the acrylic screen there so as the 1500v cannot jump out and hit the guitar !?? Basically. Explosions.... and to protect against those moments when you lose the respect.... I'll just unclip this <BANG!> There are two types of people. Those who know that you need a screen if you're going to clip lead such an amplifier..... and dead people. Such high DCV is scary IMO. 2
Guest Posted November 13, 2015 Posted November 13, 2015 @@davewantsmoore Would have to agree, had a few experiences with HV DC on commercial solar and EHV Switchyards, at even only a few amps, scary kills instantly.
mwhouston Posted November 14, 2015 Posted November 14, 2015 (edited) Finished the Decware inspired EL84 power amp with attenuation. My twist was to make a it a EL84 SE UL (not triode). Also I upgraded the PS a little. One PS tweak was to use a Russian PIO 4uf cap as the first cap in the PS. Also the larger electros are all snubbed. The inter-stage caps are Audio Note Tin foil, mylar and oil. The amp I called "Tamarisk" - just like how it sounds. The finished amp looks good and not too heavy. Sound is a big step up from my already great sounding 6V6 - Ozzie tube SE UL amp. On live classical every part of the music has a layer. There every instrument is heard in its own layer and decay, reveb etc also have their own layers. If I had have paid $5K for this amp it sounds like what I would expect for that money. Edited November 14, 2015 by mwhouston 6
bvuka2013 Posted November 14, 2015 Posted November 14, 2015 Mark, you've done it again! Love reading about your builds 1
mwhouston Posted November 14, 2015 Posted November 14, 2015 Mark, you've done it again! Love reading about your builds This would be a great amp if you still had the Fostex horns. It plays really loud on my Beymas (98db efficient).
bvuka2013 Posted November 14, 2015 Posted November 14, 2015 I might be in touch for a specialist valve amp build in the near future... Yes, I miss those Fostex horn speakers...damn wife!! 1
Dean Gale Posted November 14, 2015 Posted November 14, 2015 I purchased a pair of realistic olympus t100 expressly for the cabinet which is absolutely beautiful condition. I intend, having read that the two woofer are 16ohm types to replace all the drivers and add a midrange. I had previously bought an accusound DL890, 3 way 4 speaker crossover for the purpose. However being a first timer I'm fumbling in the dark. So I got the a) sealed cabinet I wanted b) crossovers now for the c) part. Lean on the D.Y.I. here at Stereonet. Lol. Sent from my SM-T113 using Tapatalk
mwhouston Posted November 14, 2015 Posted November 14, 2015 I might be in touch for a specialist valve amp build in the near future... Yes, I miss those Fostex horn speakers...damn wife!! I've just taken delivery of 15" Concentric Beymas, 99db efficient. I'm having some cabinets made but large. My current 12" Beymas 98db efficient may be up for sale later in the year. The new amp plays loud on the current Beymas. 1
mwhouston Posted November 16, 2015 Posted November 16, 2015 Performed a few tests on the amp (Tamarisk) all into 8.1ohm resistive load. -3db frequency points are 24Hz to 36KHz. Max power is 2.6W RMS. Gain is 21db.
Newman Posted November 16, 2015 Posted November 16, 2015 Something simple: a 10-pack of poly film caps to replace a bipolar electro, used as a DC blocker on a compression driver. At least the wiring is not so wimpy any more.... 7
Owen Y Posted November 16, 2015 Posted November 16, 2015 Any difference in sound, Newman? Cheers, Owen Dark Lantern blog - http://darklanternforowen.wordpress.com/
mwhouston Posted November 16, 2015 Posted November 16, 2015 (edited) I've paralleled 10 X 10uf polies to get 100uf. Then done that twice. Edited November 16, 2015 by mwhouston 1
Guest Posted November 16, 2015 Posted November 16, 2015 (edited) Sound lounge a month down the track, going well, ready for plaster almost, changed the way the room reacts to SPL quite profound. Edited November 16, 2015 by Guest
Guest Posted November 16, 2015 Posted November 16, 2015 The trick is define "guitar amp" .... here's Tubelab testing his 833A monster. 1500VDC is frightening stuff..... but putting it through that yellow clip lead?! <madness> Holy crap, that makes my electronic dabblings look very safe... I guess the difference is he knows what he's doing hahahahah Haha Yeah
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