I have been contimplating building another red board with more power, but have been a little hesitant with my limited experiance. That said, I'm in with some support! I would love to build one in the 100-150 wpc range!
Al
Al
Hey all, haven't built an amp in almost 6 months (moving house, changing jobs, etc) and recently I was reminded of how therapeutic of a process that I find it to be. I was flicking through the pages of this forum and I was reminded of the red board.
Anyway, looking at building a version running 6HJ5 outputs, just wanting to make sure I get the correct parts and put it together minus fire…
Reading through the thread, I'm thinking a B+ of 425v, will 200mA be okay? I considered 450v, but that involves going up to 500v caps and driving the tubes harder. At 425v I'm guessing we're looking at the 50w range, which is plenty for me.
Obviously the filament supply would have to come up, I'm thinking 11 or 12 amps of 6.3v to be safe.
If I've figured this correctly (still haven't quite got my head around the B+ supply deal) then I'd be wanting a 650/100 at 200mA and 6.3 at 12A or so.
Not entirely clear was OPT. The original is 8,000 ohm, I've seen 6,600 ohm and 6,000 ohm. Any guidance? Around the 50w range.
The alterations to the board and components weren't entirely clear either. I know George said he'd put up the full details of his alterations with pictures if there was interest, don't think that's been done yet?
Anyway, looking at building a version running 6HJ5 outputs, just wanting to make sure I get the correct parts and put it together minus fire…
Reading through the thread, I'm thinking a B+ of 425v, will 200mA be okay? I considered 450v, but that involves going up to 500v caps and driving the tubes harder. At 425v I'm guessing we're looking at the 50w range, which is plenty for me.
Obviously the filament supply would have to come up, I'm thinking 11 or 12 amps of 6.3v to be safe.
If I've figured this correctly (still haven't quite got my head around the B+ supply deal) then I'd be wanting a 650/100 at 200mA and 6.3 at 12A or so.
Not entirely clear was OPT. The original is 8,000 ohm, I've seen 6,600 ohm and 6,000 ohm. Any guidance? Around the 50w range.
The alterations to the board and components weren't entirely clear either. I know George said he'd put up the full details of his alterations with pictures if there was interest, don't think that's been done yet?
Hmm. I was just looking at the Mouser site to get a rough idea of shipping (which is a whole other pain) and I noticed something rather annoying. Apparently the Ixys 10M45S is restricted for shipping to Australia. I ordered some twelve months ago with no such problem. Has anyone encountered this? Now I have to figure out how to get some here...
Yes, I have. Exactly the same story in Japan. But, I was able to buy some from a local parts dealer without any problem. 🙂
Yoshi
I'm trying to do the same.
I last got them through Active Components, but the IXCP10M45S is no longer in their system.
Struggling to find local dealers. Anyone found one by chance?
Hi Mellowtone
Yes, same problem in the UK as well!!!!
I ended up putting a WTB on this forum and ,http://www.diyaudio.com/forums/members/luvdunhill.html
Has kindly shipped me some. He may have more??? try a PM
Cheers
Yes, same problem in the UK as well!!!!
I ended up putting a WTB on this forum and ,http://www.diyaudio.com/forums/members/luvdunhill.html
Has kindly shipped me some. He may have more??? try a PM
Cheers
Have a look at shipito.com, I've used them for this kind of thing with no problem and they usually chop a heap off the postage.
No affiliation etc.
No affiliation etc.
Hi Jeff,
Here you go.
chip1stop
chip1stop - One Stop Shopping Procurement Service for Electronic Components -
Yoshi
Here you go.
chip1stop
chip1stop - One Stop Shopping Procurement Service for Electronic Components -
Yoshi
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Anyone happen to have a close-up of the correctly wired IEC? As Blueworm mentioned, it's a little bit different than Pete's on the website.
Do the MOSFETs need to be isolated with thermal pads if they're mounted to the chassis?
TIA.
Do the MOSFETs need to be isolated with thermal pads if they're mounted to the chassis?
TIA.
Depends on what mosfet you purchased. If you bought the ones pete specified in the BOM then no they should be full pack.
Before I figure out some confusing convoluted way of getting some IXYS 10M45S chips to Australia, thought I should ask if anyone else in this area of the world (Australia, New Zealand etc) needed any and were having the same problems? Figure if I'm going to all the trouble to get them I may as well offer to send some out to other diyers in the region.
I think I bought some from luvdunhill too, about a year ago. MT, if you only need 2 pieces I think I can spare a couple. If you have any spare DN2540 that would be real nice.
Guitar amp?
Hi all, I have read this entire thread and not being an engineer have made the naive assumption that this would make a dandy little stereo guitar amp that a guy like me could put together. I obviously have much more reading to do on this forum and don't expect to be spoon feed but if there is a reason not to or modifications that it would need perhaps you could toss me a few hints for search terms so I can expand my understanding as to why. thank you for any direction you can point me to.
Doug🙂
Hi all, I have read this entire thread and not being an engineer have made the naive assumption that this would make a dandy little stereo guitar amp that a guy like me could put together. I obviously have much more reading to do on this forum and don't expect to be spoon feed but if there is a reason not to or modifications that it would need perhaps you could toss me a few hints for search terms so I can expand my understanding as to why. thank you for any direction you can point me to.
Doug🙂
Just dropping in. My version of DCPP is mid-ways to done. Not using the red board (sorry Pete), but that frees me to change anything I want.
My first car was a 1953 Chrysler Imperial with a 331ci hemi (180 HP). Mohair interior had the wonderful ability to absorb odors of any kind and still smell like an old Chrysler.
I bought some nice Heathkit AA-100 output transformers, which ought to work a treat in this amp.
My first car was a 1953 Chrysler Imperial with a 331ci hemi (180 HP). Mohair interior had the wonderful ability to absorb odors of any kind and still smell like an old Chrysler.
I bought some nice Heathkit AA-100 output transformers, which ought to work a treat in this amp.
The red board, or any HiFi amp intended for use with a CD player, computer sound card, iPOD, or other line level device (most amps discussed in this forum) will not work directly as a guitar amp. Some type of preamp is needed. There are preamps made just for this purpose. I use an old ADA MP-1 that I bought used on Ebay several years ago. The "sound" of a specific guitar amp is determined by the circuitry it uses, and the type of components used, mostly the transformers. A set of guitar amp output transformers may be a good idea.
Mine was a 1949 Plymouth with a Flathead 6. Teenagers usually kill their first car in short order, but I had that one for over 20 years. I got it in 1970 and I remember watching the Challenger space shuttle explode through the windshield from the Motorola parking lot (1986).
I made a promise to build an amp using the red board. I got the board. Most requests were for an amp in the 100 WPC range. I can think of a dozen ways to do this, but most would need a set of 100 watt OPT's in the 3300 ohm range. I'll probably order a set of Edcors but that will take a couple of months. Meanwhile I'll use something I have. Breadboarding and testing will be done on the built board that I have working now. I haven't killed it yet.
My wife has been away caring for her mother for most of this year. She is home now for the next 2 weeks, so no amp building will occur.
I bought a 48 Plymouth in 1973 (a second car to go with my Chrysler). It was in horrible shape, but would keep going through anything. It listed a few degrees to port. Sold it to my younger brother. Dad was none to pleased to have it around.
Interesting recollection regarding Challenger. One of those moments we remember.
Interesting recollection regarding Challenger. One of those moments we remember.
I remember how clear and cold it was walking across the parking lot while thinking that it was about launch time. We are about 200 miles south of the cape, but some launches are visible if the weather is clear. This one was perfectly clear and the cloud formed by the explosion hung in the sky for over an hour.
There are a few events that seem to be vividly burned into non volatile memory. I vividly remember sitting in the passenger seat of a VW van, turning on the radio to find no music. JFK had been shot.
My grandmother gave my the 49 for a HS graduation gift. I took it to the drag strip where I turned a blistering 22+ seconds. After blowing it up a few times and rebuilding it with "improvements" (sort of like the red board) I was running 17's with the original 218 CI flathead.
My fondest "Mopar memory" involves not a Hemi-head, but a redhead, heh, heh...
I am now working on a MS in Civil Engineering and my program is located in a building named for the late Dr. Ronald McNair, who was one of the seven lost aboard Challenger. Downstairs in a small case, his karate club badge is displayed - one of the countless pieces of debris from that tragedy. Most students walking past that display weren't even born the day that patch fell from the sky. I remember that day vividly, though, and I often pause to look at it and reflect.
I've been following the "Saga o' the Red Board" with great interest for some time now, and I'm now torn between the Tubelab SE and the Red Board. Decisions, decisions... 🙂
I am now working on a MS in Civil Engineering and my program is located in a building named for the late Dr. Ronald McNair, who was one of the seven lost aboard Challenger. Downstairs in a small case, his karate club badge is displayed - one of the countless pieces of debris from that tragedy. Most students walking past that display weren't even born the day that patch fell from the sky. I remember that day vividly, though, and I often pause to look at it and reflect.
I've been following the "Saga o' the Red Board" with great interest for some time now, and I'm now torn between the Tubelab SE and the Red Board. Decisions, decisions... 🙂
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Well that should be a fairly easy decision since those two amps are about polar opposites!
The Tubelab SE has the typical DHT sound. The 45 version is my favorite and works well with high efficiency speakers. It sounds exquisite on my friends Lowther based horns, reproducing everything from mellow to metal with ease. It doesn't have the power to crank my 87 db Yamahas very loud. The 300B version boosts the power to 8 watts, but it is still not earth shattering with 87db speakers. It is however loud enough to annoy my wife.
The red board can be built in versions from 15 WPC to 250 WPC. It can set high efficiency speakers on fire! The sound is punchy and dynamic. It ROCKS, if you like that sort of thing. It sounds great on the Yamahas, but the amp I have been using the most lately is the Simple P-P.
I am slowly working on two different sets of high efficiency horn speakers, so the 45 amp will see a lot more use soon.