starcat
-
Posts
246 -
Joined
-
Last visited
Content Type
Profiles
Forums
Events
Posts posted by starcat
-
-
I can get real LSK389A for 12 Euro the piece. Will be ordering some, so If anyone is interested PM me.
-
Yeah, sure kOhm (still in sailing mode, returning home tomorrow and back to amp building :-)
I have a T2 PCB that accepts only the DACT or the RK50 with a pre-drilled front panel as well. So, "has" to be one of the two.
John, what do you like on the Goldpoint V47 better?
-
1
-
-
On 7/9/2021 at 2:01 AM, Kerry said:
Here's a new twist on my T2 build. I've added both the HE-90 jack as well as a custom built Teflon HE-60 jack with appropriate voltages/resistances.
This one is in black chrome
Congrats, Kerry. That one looks gorgeous!
Are you using all original transistors or modified boards with substitutes?
Digital attenuator or analog pot in there?On 7/3/2021 at 12:02 PM, Craig Sawyers said:That is an expensive pot for sure. Mouser are expecting 8 of them in September for UKP729 (so about $1k)
I think I ended up using a DACT switched attenuator. The RK50 was just too hot for my pocket.
Indeed, way overpriced by now. In fact the almost only reason I decided to go with the RK50 is that it is still available in quad 50 ohm and 50 ohm is what the T2 was designed for.
810€ at Mouser plus 20 VAT, makes up for stunning 972€ for a pot.
-
-
Anyone can recommend some nice (low voltage) contact closure buttons with build in LEDs that might be used on front panels? Like these for example...
-
Anyone tried the Dynalo Mk2 through-hole with Xicon 273 resistors? All the RN60Ds are 100ppm where the Xicon 273 are 50ppm, 1/2w... and cheaper as well.
-
On 6/29/2021 at 3:55 AM, Sebtdi said:
I was able to replace a Zener diode to 100V instead of 130V - now have 580V bias supply
Thanks to Kerry for his assistance!
Very nice, congrats!
Are you building the amp and PSU in separate chassis?
Need moar pics 🙂 -
Hey John,
I have the HE-6 but not yet 🙂 the CFA (it is on my build list however).
I am ising the HE-6 with RSA The Dark Star atm and it is just magnificent. Compared it to the HD-800 as well but clearly prefer the HE-6 and traded the HD-800.
-
2
-
-
What pot impedance has the T2 be designed for? I can get the quad RK50 in 50 ohms only but not in 10. Anyone has one for sale?
14 hours ago, JoaMat said:Also, putting battery 22K resistors on the tube side elevated half an inch makes it perfect for using clip leads when setting the voltage to 6.55V.
Thanks, JoaMat. I see me already changing the 22K R42 to the other side of the board 🙂
-
No pictures, not even posts anymore... c'mon guys, don't be shy and show off your work 🙂
-
On 6/7/2021 at 7:20 AM, Blaino said:
G2R1000MT17D GeneSiC Semiconductor | Discrete Semiconductor Products | DigiKey
Will this serve as a sub for the C2M1000170D? Looks very similarly rated except for power dissipation of 44W instead of 69W.
Looks good. Have you tested it already?
The G3R450MT17D is a replace as well. It was mentioned somewhere above.
-
Phew, soldered some 50x LEDs... Checked the C3675 and A1468 for breakdown voltage. Will use the ones with the highest in the batteries.
Are there any fakes of the C3381 and K246 and is there any special procedure for testing those?
I mounted only 4 of the total 8 standoffs as the ones close to the front panel are in the way of the Stax connectors and the ones in the back are exactly where the Amphenol connectors are. 4 of them should be fine I think.
-
3
-
-
Preparing 4 layer board out of the 3 layer attenuatorsmtv42flipground7.zip as follows. Any other tips that I should take care for, like impedance controlled PCB?
Going with thickness of 1.6mm and 1oz copper for the top and bottom layers and 0.5oz per each of both mid layers.
-
Anyone has balanced boards left, empty or populated? Please PM
-
Yeah, EL34. I have as well 4.5 and 1.5 amps per tube for the transformer secondaries. Sorry for typo, doing too many things at once right now 🙂
-
The EL84 would be even more with current draw at 4.5A or 9A per pair.
But because each tube sits on its own wire and transformer winding it is 1.5A respectively 4.5A per 6CA7 or EL84 tube.
So, Craig out of both wires given, would you for the umbilical go with the
- Cal Test 0.5mm2 20AWG 1KV 10A silicon wire or with the
- bulkwire.com PTFE 600VAC wire which I have 20AWG for the smaller tubes and 18AWG for the EL34s?
-
1KV and 10A rated silicon wire from Cal Test, 20AWG, 0.5mm2 conductor and 2.7mm OD for use with the heater AC wires: https://www.mouser.at/ProductDetail/510-CT2884-0-10
Compared to the PTFE wire it has double the thickness, 2.7mm vs. 1.37mm, both 20AWG, while 18AWG PTFE would be 1.67mm OD.
Using two wires each 1KV makes it 2KV wire to wire. Using two 600V wires make it 1.2KV which is pretty much good to go for both the +/- 500VAC heater wires, as they are both insulated; correct me if I am wrong.
-
Thanks, Craig! I also thought wire to wire with 2x 600V should be ok. But would get the extra fiber glass insulation if I could find it.
-
I thought that the 600V PTFE wire was that everybody used, KG as well, no? That extra insulation would be nice to know what part no is it and where to get. I was randomly searching at Mouser but couldn't find anything suitable.
Found here the Cal Test silicone wire 0.75mm 20AWG 10m black, pretty thick at 3.7mm OD. Looks pretty thick for that Amphenol connector, btw.
-
On 6/16/2019 at 4:54 PM, sbelyo said:
I wouldn't mind doing a run for all the boards needed for a complete system with volume control and source selection. I know Kerry was working on or has code for the volume control
Any plans for a group buy?
Any bare or assembled boards available for sale?
Anyone has an updated BOM or are any of the parts unavailable by now?
-
On 1/6/2021 at 2:52 AM, Pars said:
On my Pass Aleph P, the XLR grounds both go to board ground. Same on Kerry's SS Mini. I haven't had any hum problems whatsoever on my stuff, but everyone has different issues potentially.
That's the proper way of doing it in fully balanced equipment, chassis is separated from circuit ground and for shielding purposes only. Chassis goes then centrally to the star earth grounding (mostly in the PSU), where also circuit ground centrally may or may not go to (through a 10R resistor).
99% of the time Rane is not fully balanced but SE equipment using only balanced for I/O.
-
I am using silver plated stranded copper wire, PTFE insulation rated for 600VAC, mil-spec, wall thickness .25mm, temperature rating up to 200°C (392°F). Probably good enough for both wires against each other.
-
I am using this 15mm polyester sleeve from HellermannTyton for the cable above and considering using it for the T2 umbilicals as well. I don't have any additional sleeving inside the outer sleeve for special wires. I have twisted the 6.3V AC heater wires inside. Anything else I should take care for?
This sleeve is very nice and is available in 25mm and 35mm as well.
-
Yeah, they take a long time but are fun to make 🙂 I just completed the umbilical for the BHSE I am building (with original HeadAmp boards) and it took long as well despite using an AMP connector with crimp type pins. To be honest, I liked that connector much more than the Amphenol we use for the T2. It is like cutting wires, crimp pins on both sides and insert into the connector housing and voila. The pins are automatically isolated within the connector housing as well, so no fiddling with shrink tubing or soldering into the connector and the pins are available for different AWG sizes as well. A very nice system.
Craig, do you have any part number for that special glass fiber insulation and how long are your umbilicals? I am planning for 90cm, 3ft.
KGSSHV Carbon Build Thread
in Do It Yourself
Posted · Edited by starcat
Congrats, indeed a very nice build!