Sub Sonic Posted March 31, 2021 Posted March 31, 2021 (edited) 15 minutes ago, ssb102 said: Which one did you buy? From where? How much? It’s the Bluecarve Bluey with size and X axis upgrade. I can highly recommend Adam, he is super helpful with backup for his customers. The machines are made in Australia too, using Australian aluminium. The standard machine is around $1500 (750 x 750) but by the time the upgrades, router, extra bits and bench are added, it’s getting closer to $3k. As supplied (standard), you really only need to add a spindle/router and base boards. 6-8 carbide bits are included in the purchase and most people would have a laptop or PC they could use. Edited March 31, 2021 by Sub Sonic
Sub Sonic Posted March 31, 2021 Posted March 31, 2021 15 minutes ago, Gryffles said: @Sub Sonic you lucky bugger. Will you be keen to do jobs for other people? Not really sure at this stage, I really want the router to be fun rather than a job, so we’ll see how we go 1
Gryffles Posted March 31, 2021 Posted March 31, 2021 8 minutes ago, Sub Sonic said: Not really sure at this stage, I really want the router to be fun rather than a job, so we’ll see how we go Yeah I don't blame you for that. Let us see how you get on with it anyway 1
mwhouston Posted March 31, 2021 Posted March 31, 2021 Wondered why this new and a not so new tube MM phono stage had a slight hum when in the past similar builds were dead silent. Then noticed when I brought my hand to the open bottom chassis of the new one the hum increased. In the past these were built in solid metal enclosed cases. Silly me, of course these sensitive, high gain devices need a ground plane. Here is the bottom plate I have made for this phono pre and another. I sprayed it the same colour as the top plate. Now much quieter. http://retro-thermionic.blogspot.com/2020/12/mantra-kit-tube-mm-phono-preamp.html 2
aussievintage Posted March 31, 2021 Posted March 31, 2021 2 minutes ago, mwhouston said: Wondered why this new and a not so new tube MM phono stage had a slight hum when in the past similar builds were dead silent. Then noticed when I brought my hand to the open bottom chassis of the new one the hum increased. In the past these were built in solid metal enclosed cases. Silly me, of course these sensitive, high gain devices need a ground plane. Here is the bottom plate I have made for this phono pre and another. I sprayed it the same colour as the top plate. Now much quieter. http://retro-thermionic.blogspot.com/2020/12/mantra-kit-tube-mm-phono-preamp.html High gain at the start of a signal chain always needs proper attention. The same sort of problem occurs with valve phono preamps, where people, these days, like to have the valves sticking up out of the chassis where they can be seen. However, put your fingers close to the first valve and you will hear hum. Even without your fingers, that first valve is picking up hum and noise from all around. Sometimes you will get hum from nearby equipment - like the turntable motor, or house wiring. I have taken to putting a shield on that first triode bottle. It must be connected to the chassis, and those old shielded valve sockets and matching aluminium cans used in old radios are a good option, but don't look great. I have some flat black ones that look at bit better. Next build I might even paint some. 1
crtexcnndrm99 Posted March 31, 2021 Posted March 31, 2021 4 minutes ago, aussievintage said: High gain at the start of a signal chain always needs proper attention. The same sort of problem occurs with valve phono preamps, where people, these days, like to have the valves sticking up out of the chassis where they can be seen. However, put your fingers close to the first valve and you will hear hum. Even without your fingers, that first valve is picking up hum and noise from all around. Sometimes you will get hum from nearby equipment - like the turntable motor, or house wiring. I have taken to putting a shield on that first triode bottle. It must be connected to the chassis, and those old shielded valve sockets and matching aluminium cans used in old radios are a good option, but don't look great. I have some flat black ones that look at bit better. Next build I might even paint some. Seems to be the way the designer went with the valve phono I have (aluminium can shielding the first valves). It is the PH16 from tubes4hifi.com... Wondered about additional shielding on the side adjacent to the Lenco, because it’s motor is certainly large enough to introduce noise into the start of the signal chain. Or some additional isolation of the pcb from the chassis... 2
mwhouston Posted March 31, 2021 Posted March 31, 2021 I’ve used these in the past. Not cheap but may get some more for the phono stage. Not earthed but some shielding and good looking. 2
aussievintage Posted March 31, 2021 Posted March 31, 2021 21 minutes ago, crtexcnndrm99 said: Seems to be the way the designer went with the valve phono I have (aluminium can shielding the first valves). It is the PH16 from tubes4hifi.com... Wondered about additional shielding on the side adjacent to the Lenco, because it’s motor is certainly large enough to introduce noise into the start of the signal chain. Or some additional isolation of the pcb from the chassis... You should try the motor on my B16H Rek-o-kut. Huge. If you want to try it with some valve cans, because the preamp seems to use ceramic sockets with no metal housing, you will need to provide the grounding by other means. I usually clip one of those mini-alligator clip test leads onto the can, then onto a screw on the metal chassis, or the phono sockets. 1
aussievintage Posted March 31, 2021 Posted March 31, 2021 1 minute ago, mwhouston said: I’ve used these in the past. Not cheap but may get some more for the phono stage. Not earthed but some shielding and good looking. They do look fancy. However, metal cans do practically nothing until you ground them. In fact, sliding one on while the amp is live, it will actually couple your fingers to the valve, and make the hum worse, until the moment when the can connects to the base (or you clip on a ground lead)
Red MacKay Posted March 31, 2021 Posted March 31, 2021 Well you lads all say these things, but my built on a piece of wood 10Y DHT pre has no shielding anywhere and is quiet as! Maybe I just got lucky. 3
aussievintage Posted March 31, 2021 Posted March 31, 2021 9 minutes ago, Red MacKay said: Well you lads all say these things, but my built on a piece of wood 10Y DHT pre has no shielding anywhere and is quiet as! Maybe I just got lucky. A standard preamp can get away with it. It's all about how much gain is downstream before you get to the speaker. A phono preamp, first stage, is at least 40dB further away, so any little noise will be heard. 1
mwhouston Posted March 31, 2021 Posted March 31, 2021 19 minutes ago, aussievintage said: A standard preamp can get away with it. It's all about how much gain is downstream before you get to the speaker. A phono preamp, first stage, is at least 40dB further away, so any little noise will be heard. From frightening personal experience preamps with DHT tubes almost have no gain. OK, phono preamps have huge gain. I think I’ve tamed mine.
RankStranger Posted April 1, 2021 Posted April 1, 2021 Mostly finished my chip amp. Has a slight hum which I’ll try to sort out but nothing dramatic. Still need to do some cleaning up and anodise the heatsink black and clear anodise the side panels. I’m pleased with how the smoked acrylic lid came out. The blue power leds coming through it look boss. I’m going to call it the A4 because it’s almost the same footprint as an A4 sheet of paper 7 1
btd Posted April 1, 2021 Posted April 1, 2021 Nice one. What set up on the inside did you end up with?
RankStranger Posted April 1, 2021 Posted April 1, 2021 12 minutes ago, btd said: Nice one. What set up on the inside did you end up with? thanks. I forgot to snap a shot before I put the lid on but this is a work-in-progress shot from yesterday showing the layout. The chips are now mounted under the angle on the right which is a bit of a pain but I didn’t want any more holes in the feature heatsink 2
itsparks Posted April 1, 2021 Posted April 1, 2021 2 hours ago, RankStranger said: thanks. I forgot to snap a shot before I put the lid on but this is a work-in-progress shot from yesterday showing the layout. The chips are now mounted under the angle on the right which is a bit of a pain but I didn’t want any more holes in the feature heatsink Those look like the BrianGT chip amp psu boards... 1
RankStranger Posted April 1, 2021 Posted April 1, 2021 5 hours ago, itsparks said: Those look like the BrianGT chip amp psu boards... sure is. Good spot. I picked the kit up as an half-finished project off gumtree last year between lockdowns.
mwhouston Posted April 1, 2021 Posted April 1, 2021 10 hours ago, RankStranger said: Mostly finished my chip amp. Has a slight hum which I’ll try to sort out but nothing dramatic. Still need to do some cleaning up and anodise the heatsink black and clear anodise the side panels. I’m pleased with how the smoked acrylic lid came out. The blue power leds coming through it look boss. I’m going to call it the A4 because it’s almost the same footprint as an A4 sheet of paper I’ve never thought the inside of amps is pretty and therefore never installed a see through top. But a blue glow coming up though the Smokey Perspex may not be so bad. 1
RankStranger Posted April 2, 2021 Posted April 2, 2021 (edited) 1 hour ago, mwhouston said: I’ve never thought the inside of amps is pretty and therefore never installed a see through top. But a blue glow coming up though the Smokey Perspex may not be so bad. It’s definitely not pretty - - but in normal light you can’t see through it. It just looks kind of black and I think with the black heatsink next to it, it will mostly read as black. the shot I posted last night was with a kitchen light directly above it. It was just an experiment anyway. I was inspired by the Sparkler Audio designs. Which actually grew out of 47 Labs, the original popularisers of chip amps so it’s kind of appropriate. http://sparkler-audio.com/portfolio/products_en.html Edited April 2, 2021 by RankStranger 2
mwhouston Posted April 2, 2021 Posted April 2, 2021 (edited) 50 minutes ago, RankStranger said: It’s definitely not pretty - - but in normal light you can’t see through it. It just looks kind of black and I think with the black heatsink next to it, it will mostly read as black. the shot I posted last night was with a kitchen light directly above it. It was just an experiment anyway. I was inspired by the Sparkler Audio designs. Which actually grew out of 47 Labs, the original popularisers of chip amps so it’s kind of appropriate. http://sparkler-audio.com/portfolio/products_en.html Ive built a number of chip amps and just recently finished a 100W module kit. Yet to be finished as a working amp. One build I do like is in a 1U 19” rack mount. Super slim and I have a machining SS preamp/headphone amp to go with it. http://audiobastard.blogspot.com/2007/10/synergy-chip-amp.html http://retro-thermionic.blogspot.com/2019/07/overture-lm4780-chip-power-amp.html Edited April 2, 2021 by mwhouston 1
RankStranger Posted April 2, 2021 Posted April 2, 2021 16 minutes ago, mwhouston said: Ive built a number of chip amps and just recently finished a 100W module kit. Yet to be finished as a working amp. One build I do like is in a 1U 19” rack mount. Super slim and I have a machining SS preamp/headphone amp to go with it. http://audiobastard.blogspot.com/2007/10/synergy-chip-amp.html http://retro-thermionic.blogspot.com/2019/07/overture-lm4780-chip-power-amp.html in a 1U those toroids must be like drink coasters! Are they special slim ones? So much room! That looks much less infuriating to work on than mine 1
mwhouston Posted April 2, 2021 Posted April 2, 2021 21 minutes ago, RankStranger said: in a 1U those toroids must be like drink coasters! Are they special slim ones? So much room! That looks much less infuriating to work on than mine Low profile from Altronics. 192VAC (I think). 1
mwhouston Posted April 2, 2021 Posted April 2, 2021 26 minutes ago, mwhouston said: Low profile from Altronics. 192VAC (I think). https://www.altronics.com.au/p/m5371-powertran-24v-192va-low-profile-toroidal-transformer/
mwhouston Posted April 2, 2021 Posted April 2, 2021 Having great success drastically reducing hum in a new tube phono stage with a ground plane (earthed bottom plate) I have done the same with a slightly older EAR834p kit tube phono preamp. With the EAR (“Calibre - 834”) earthing (HT negative) the chassis and installing a ground plane has silenced the phono stage completely. I also replaced the buffer tube (three stage phono preamp) with a Raytheon 12AU7. With this tube having half as much gain any noise upstream will be reduced. At the mo even with vol way up there is no hum, hiss or anything. http://retro-thermionic.blogspot.com/2019/03/calibre-834-tube-phono-mm-preamp.html
Steffen Posted April 2, 2021 Posted April 2, 2021 2 hours ago, mwhouston said: https://www.altronics.com.au/p/m5371-powertran-24v-192va-low-profile-toroidal-transformer/ Strangely, I can’t get into Altronics’ website, their Barracuda WAF isn’t letting me in. When clicking the link above (or going straight to https://altronics.com.au) I get: I’m with Aussie Broadband. Is anybody else having this issue? Incidentally, we had a brief Internet outage earlier today, I wonder what’s going on at Aussie...
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