What a sight🙂 Cant wait to get my hands on those🙂 Thanks a lot to the Twisted pair, for all the efforts doing this😎
Steen🙂
Hello, I have just hopped into this threat and ordered a kit (understood that that was still possible).
Still gotta lot of reading to do. A little question: is it possible to have two sets of line-out (like some pre, eg Pass). Maybe have a switch to select between them?
edit. oops I see this was already covered
http://www.diyaudio.com/forums/showthread.php?postid=799285#post799285
🙂
I think I will be using this for a volume control/input selector. Any comments on that (is it good enough?)
http://www.rt-audio.nl/easypage_7.html
Still gotta lot of reading to do. A little question: is it possible to have two sets of line-out (like some pre, eg Pass). Maybe have a switch to select between them?
edit. oops I see this was already covered
http://www.diyaudio.com/forums/showthread.php?postid=799285#post799285
🙂
I think I will be using this for a volume control/input selector. Any comments on that (is it good enough?)
http://www.rt-audio.nl/easypage_7.html
Just for information since I have gotten quite a few emails, yes there are still plenty of kits and PCBs available. 🙂
Cheers!
Russ
Cheers!
Russ
My initial buy for parts was 25 kits (+ for some parts). When we hit 20 kits sold, I will be ordering another 25 kits worth, so fear not... 😉
I took the plunge and ordered one of the fancy r-core transformers from Hong Kong.
R80-34 primary (0-115) x 2 /SCN: (30-20-0-20-30)X2(1A).0-15 X2(1A).0-9 (1A)
http://eshop.diyclub.biz/product_info.php?cPath=152_74&products_id=56
The website was easy to use and they speak English if you have a question and need to call them, which I did to confirm inventory. One hint: if you order through the web, besure to copy and past the Trafo part number and type of shipping into an order comments box provided during the shopping cart process. Hong Kong Post by boat is fairly reasonably priced.
I like the trafo since a 60vac and 20vac secondary can be formed for the twisted pair board, and 9vac for a regulated 5VDC supply to power the digital controls and relays.
Pretty cool.
-David
R80-34 primary (0-115) x 2 /SCN: (30-20-0-20-30)X2(1A).0-15 X2(1A).0-9 (1A)
http://eshop.diyclub.biz/product_info.php?cPath=152_74&products_id=56
The website was easy to use and they speak English if you have a question and need to call them, which I did to confirm inventory. One hint: if you order through the web, besure to copy and past the Trafo part number and type of shipping into an order comments box provided during the shopping cart process. Hong Kong Post by boat is fairly reasonably priced.
I like the trafo since a 60vac and 20vac secondary can be formed for the twisted pair board, and 9vac for a regulated 5VDC supply to power the digital controls and relays.
Pretty cool.
-David
Kit Price, Volume Pot & r-core transformers from Hong Kong.
I have bought their r-core transformers before, so far so good !
I would like to know what is status of choicing the "volome pot"
What is the price of
i) Full kit (2 main bds, 2 pwr bds included the parts and PCB)
ii) Pricr of PCB only
Thanks !
Thomas
I have bought their r-core transformers before, so far so good !
I would like to know what is status of choicing the "volome pot"
What is the price of
i) Full kit (2 main bds, 2 pwr bds included the parts and PCB)
ii) Pricr of PCB only
Thanks !
Thomas
I think Brian is in the midst of a site upgrade. The site should be back up soon.
I forget the exact price for complete kit but a complete set of PCBs are $49 for 2xpreamp and 2 x PSU plus shipping. I am sure Brian will chime in soon.
I am currently working on attenuator for the preamp, but that will be in a different thread.
Also in the works and neary done is a balanced/SE source selector with 6 inputs and 2 outputs with dual independant internal/external loops for preamps and such.
Both the SS and the attenutor are being designed to work together.
Cheers!
Russ
I forget the exact price for complete kit but a complete set of PCBs are $49 for 2xpreamp and 2 x PSU plus shipping. I am sure Brian will chime in soon.
I am currently working on attenuator for the preamp, but that will be in a different thread.
Also in the works and neary done is a balanced/SE source selector with 6 inputs and 2 outputs with dual independant internal/external loops for preamps and such.
Both the SS and the attenutor are being designed to work together.
Cheers!
Russ
Full kit price is $165, and includes all components to stuff the boards, as well as all mounting hardware, faston connectors, heatsinks for the PS board and kapton insulators for all the fets. The only think not in the kit are case, wire, trafo, heatsink for the pre (can use case wall or anyother flat hs) and connectors (rca/xlr).
The web site appears to be partly a DNS problem and partly a configuration issue. Working on it.
The web site appears to be partly a DNS problem and partly a configuration issue. Working on it.
I have also been asked about whether our kit will work with Kari's boards. I have not done a complete comparison, but this is what the main differences appear to be:
I think kari's boards used MUR diodes in the PS and we supply 1N4004 diodes (sould work fine on his boards).
Also, we use a single 75V and 24V zener and supply a bunch of 0-ohm resistors to fill the extra spaces. Again, should be fine.
Kari's boards use TO-220 heatsinks for the pre boards, where our uses any flat hs (all fets are mounted along the board edge). You would need to get those heat sinks, but they are available all over the place (try ebay). You would also need to get screws, nuts and shoulder washers to mount them, as our kit only has them for the ps heat sinks. It does include the insulators though.
Not sure about the mounting hardware, but as long as his boards have 4 holes per board, that should be fine.
If someone wants to do a more exaustive comparison, it would be welcomed.
Parts alone would be $116 ($165-$49). I am still hopeful we will get parts from Coulomb some day, but I'll let that one go for now 😉
I think kari's boards used MUR diodes in the PS and we supply 1N4004 diodes (sould work fine on his boards).
Also, we use a single 75V and 24V zener and supply a bunch of 0-ohm resistors to fill the extra spaces. Again, should be fine.
Kari's boards use TO-220 heatsinks for the pre boards, where our uses any flat hs (all fets are mounted along the board edge). You would need to get those heat sinks, but they are available all over the place (try ebay). You would also need to get screws, nuts and shoulder washers to mount them, as our kit only has them for the ps heat sinks. It does include the insulators though.
Not sure about the mounting hardware, but as long as his boards have 4 holes per board, that should be fine.
If someone wants to do a more exaustive comparison, it would be welcomed.
Parts alone would be $116 ($165-$49). I am still hopeful we will get parts from Coulomb some day, but I'll let that one go for now 😉
Member
Joined 2002
Member
Joined 2002
I got another question will this pre-amp get hot ? Will it require a big heat sink ?
My idea is to use my new chassis i bought a few months ago to house these to pre amp's and Digital Volume pot.
My idea is to use my new chassis i bought a few months ago to house these to pre amp's and Digital Volume pot.
Hi Russ,
Sorry for the delay in replying to your email.
As requested and I hope some of the others are interested, I would be very much interested in the above.
I am currently working on attenuator for the preamp, but that will be in a different thread.
Also in the works and neary done is a balanced/SE source selector with 6 inputs and 2 outputs with dual independant internal/external loops for preamps and such.
Please keep us posted.
Regards
Ian
Sorry for the delay in replying to your email.
As requested and I hope some of the others are interested, I would be very much interested in the above.
I am currently working on attenuator for the preamp, but that will be in a different thread.
Also in the works and neary done is a balanced/SE source selector with 6 inputs and 2 outputs with dual independant internal/external loops for preamps and such.
Please keep us posted.
Regards
Ian
When I built mine I simply mounted the FET's to the bottom plate of the chassis. When the chassis has plenty of air circulation around it, you can barely feel a temperature increase of the chassis. When stacked in with other equipment, the chassis feels warm to the touch, but doesn't get anywhere close to being hot to the touch.
For those who like numbers, the cascode FET's disspate about 1.5W each, the gain FET's about 1/4W each. Off the top of my head I don't have the numbers for the Power Supply Fet's. I see if I can dig those up!
Cheers, Terry
By the sounds of it, a piece of u-channel aluminum (maybe 1" wide x 5-6" long) would probably be fine as a heatsink for each pre channel... It would get a little warmer, but probably not hot. I'll try it out once I get a board built up, which should be any day now.
One thing I had considered (but I think I may actually do something differen now) is simply mounting the fets to each side of the case. So you would have one channel on one side and the other on the other with the two PS in the middle.