I saw that on your website. That amp is a ways off in the future. I might need more height, but your chassis is the only thing out there that can handle the weight. Maybe some more creative packaging will be needed.
I haven't weighed all the transformers yet......I might need a built it fork lift.....Or I might need to make it into two mono blocks, but then it wouldn't be a "kilowatt in a box."
I had to leave all of the workbenches, shelving, racks and stuff behind and give away or sell a lot of stuff when we left Florida. We put the house on the market for more than I thought it was worth, and got a cash offer quickly with a 3 week move out date. We have moved twice in the past 18 months and I can't find squat. I do know where the Landfall chassis and most of the parts for the half built amp is, but I can't find the transformers.
In Florida, I did everything in a 10 X 10 foot room. Now I have over half of a 2000 square foot basement, I just have to build it all out. One and a half workbenches are done........
Have a look at the Eimax 3CX tubes e.g. 3CX1200A7 or 3-500Z (3kV plate, 3/4A Ipmax and 25W of grid drive needed) - have a look at Data sheets on RF Power Triodes for some others. A few pax have made PP amps from these - they were cheap 10y ago - but some impressive plate voltages on the big ones
Actually, I suspect I'm telling you to suck eggs as I suspect you've seen all this before!
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I have played with RF power tubes including the 3-500Z for RF and audio amps. I had saved some of the 4CX series (4CX250 and 4CX350) but I had planned an RF linear amp for them. They got sold and my RF amp will use MRF150's (sand based life forms).
I already have two sets of HUGE OPT's. Both pairs are 1250 ohms CT Plitron toroids, rated for 400 watts at 20 Hz. This precludes the use of big voltage RF tubes, since they would need 5000 to 12000 ohms. These OPT's were intended for 6 to 8 6550's on 500+ volts. They wouldn't take KV level B+. I'm probably stretching them a bit on 650V at 500 watts.
The amp will use sweep tubes, but just which ones and how many hasn't been chosen yet. The choice will be made from tubes that I already have plenty of (that budget thing) but that is still a big list.
I have seen 525 watts flow through these OPT's when fed by 4 X 35LR6's on 650 volts. I think 6 of them per channel would be needed for long term reliability. I have about 50 of them and I got them cheap.
If 4 X 36LW6 will run at that power continuously for a few hours, I may consider them, but they may bee too tall for the Landfall box unless I make an extended cage.
There are other possible combinations too, but I will start a new thread and document all the testing once I have a fully operational lab. With all the other things going on right now, that may be a few months out.
I already have two sets of HUGE OPT's. Both pairs are 1250 ohms CT Plitron toroids, rated for 400 watts at 20 Hz. This precludes the use of big voltage RF tubes, since they would need 5000 to 12000 ohms. These OPT's were intended for 6 to 8 6550's on 500+ volts. They wouldn't take KV level B+. I'm probably stretching them a bit on 650V at 500 watts.
The amp will use sweep tubes, but just which ones and how many hasn't been chosen yet. The choice will be made from tubes that I already have plenty of (that budget thing) but that is still a big list.
I have seen 525 watts flow through these OPT's when fed by 4 X 35LR6's on 650 volts. I think 6 of them per channel would be needed for long term reliability. I have about 50 of them and I got them cheap.
If 4 X 36LW6 will run at that power continuously for a few hours, I may consider them, but they may bee too tall for the Landfall box unless I make an extended cage.
There are other possible combinations too, but I will start a new thread and document all the testing once I have a fully operational lab. With all the other things going on right now, that may be a few months out.
Am I correct in believing they are yet another 807 "mutant" with bigger plates?
I keep being shocked at just how much grunt that family can produce, if the screens are properly managed. But as you say, something for another thread.
No, they are the last and biggest of the TV horizontal sweep tubes (line output in much of the world) made before the TV world went completely solid state.
The 6LW6, 26LW6, and 36LW6 themselves went through several upgrades without a type number change, or even a suffix (there is no 6LW6A). All of the upgrades involved additional heat radiating fins attached to the plate, and even a bigger bottle to hold it all. I have seen both bottle sizes and several fin sizes and types in the 6LW6 and 36LW6. I haven't seen a fat bottled 26LW6, but they may exist. The smallest of the breed will begin to show plate color at about 60 watts dissipation, while the biggest will eat over 90 watts without redness. All are rated for 40 watts.
All true sweep tubes have a sensitive screen grid that will blow up if fed B+ voltage. Most work best at 150 to 200 volts. This makes UL or triode impossible on most tubes. I have had runaway issues when attempting triode mode with the 6LW6.
Peak cathode current rating is 1.4 Amps. Can't do that with a 6L6/807 type. The 6BG6 is the sweep tube version of the 6L6/807. There are some Sylvania / Phillips ECG 6BG6's out there with 7027A internals that will eat 40+ watts. The cathode, however will only support about 300 mA.
Holy Smokes Dave
This is great news as I do all my chassis layouts in autocadd.
I'll be doing a layout in the next couple weeks and will send you a prototype for pricing. If its in cadd, do you still need a dimensional layout or will the entities suffice? Can you also do lettering on the faceplates? Can the faceplates be 1/4" alum?
This is great news as I do all my chassis layouts in autocadd.
I'll be doing a layout in the next couple weeks and will send you a prototype for pricing. If its in cadd, do you still need a dimensional layout or will the entities suffice? Can you also do lettering on the faceplates? Can the faceplates be 1/4" alum?
No dimensions required, we work in AutoCAD also.
Yes, we can engrave.
We only stock and machine 1/8" aluminum. But since you're the second guy in two weeks (and ever) to ask for 1/4" face, we'll get some longer endmills. You'd still need to provide the material though.
I will mention that if you use our standard front (faceplate), there are no exposed screws on the front of the chassis. Not the case with custom faceplates because of how they attach.
If you email us at feedback@landfallsystems.com, I'll send you an AutoCAD template to start from. Just stretch it to size and make your holes.
Yes, we can engrave.
We only stock and machine 1/8" aluminum. But since you're the second guy in two weeks (and ever) to ask for 1/4" face, we'll get some longer endmills. You'd still need to provide the material though.
I will mention that if you use our standard front (faceplate), there are no exposed screws on the front of the chassis. Not the case with custom faceplates because of how they attach.
If you email us at feedback@landfallsystems.com, I'll send you an AutoCAD template to start from. Just stretch it to size and make your holes.
Something new every day
That's a whack of watts even with a single pair in AB2. (As you pointed out earlier) Thanks!
That's a whack of watts even with a single pair in AB2. (As you pointed out earlier) Thanks!
Why use the ultra rare 13E1 in your design?.. Do you have a large stock of them or something?
13E1
Hi sorry for the late reply. Your question as to why I am using the 13E1. The front end of the amp using 6N7 into 13E1 is the best sounding amp I have ever built in 66 years. So I decided to use that tested design to drive the 833A. I had originally thought about using a GM70 but then decided to stick with what I knew would work. So the 8 pieces of GM70 that I have are now redundant and I will probably sell them as the 833 Amp will be the last one that I build. Do I have a stock of 13E1's.....I do have 20 pieces which I have had for a number of years, and again I had better get round to doing something with them before I am too old to use a soldering iron
Hi sorry for the late reply. Your question as to why I am using the 13E1. The front end of the amp using 6N7 into 13E1 is the best sounding amp I have ever built in 66 years. So I decided to use that tested design to drive the 833A. I had originally thought about using a GM70 but then decided to stick with what I knew would work. So the 8 pieces of GM70 that I have are now redundant and I will probably sell them as the 833 Amp will be the last one that I build. Do I have a stock of 13E1's.....I do have 20 pieces which I have had for a number of years, and again I had better get round to doing something with them before I am too old to use a soldering iron
Hallo 833 Friends.
I was There and could listen the Speaker with the 2x 8" and the Bayma AMT- Professional Series.
Realy realy good, but to expensive for my low Money Bugdet.
The Amp you all Know is The Silvercore produced One and The Speaker is from
LSV Lautsprechershop Achenbach- only in German.
He prefers the PLH Speaker in different Sizes mostly.
The French Guys produces a lot good Speakers- look to Focal, Davis, Audax.
Hifi-Music-World 2008
I remember that the AMT a bit Sounds like Elektrostatik Speaker.
Together with 833A was very impressing Soundstge.
It was a nice Day Meeting other Enthusiasts in Hi-Fi DIY.
Happy Building.
Regards Hagen.
I mostly reading in Threads and a bit Assembling Amps and Speakers.
I was There and could listen the Speaker with the 2x 8" and the Bayma AMT- Professional Series.
Realy realy good, but to expensive for my low Money Bugdet.
The Amp you all Know is The Silvercore produced One and The Speaker is from
LSV Lautsprechershop Achenbach- only in German.
He prefers the PLH Speaker in different Sizes mostly.
The French Guys produces a lot good Speakers- look to Focal, Davis, Audax.
Hifi-Music-World 2008
I remember that the AMT a bit Sounds like Elektrostatik Speaker.
Together with 833A was very impressing Soundstge.
It was a nice Day Meeting other Enthusiasts in Hi-Fi DIY.
Happy Building.
Regards Hagen.
I mostly reading in Threads and a bit Assembling Amps and Speakers.
833 midlife
Ah well the bug has bitten me long ago , and i have some tubes in my basement for this so also looking into this project
Yves courtiously emailed me the thread , so need sockets , the utput tranny is a bit over the budget............any other solutions ?
the powersupply i do my own SMPS , love these for today they offer so many advantages , and i have them already running on 845Se amps
Also building a 300Bse with a stacked SMPS as in my 845 so u get DRD , ok nothing new but shouold be interesting
Maybe i should start my own thread for this ?
So suggestions , welcome , next 2/3 months is the brainstorming time
Ah well the bug has bitten me long ago , and i have some tubes in my basement for this so also looking into this project
Yves courtiously emailed me the thread , so need sockets , the utput tranny is a bit over the budget............any other solutions ?
the powersupply i do my own SMPS , love these for today they offer so many advantages , and i have them already running on 845Se amps
Also building a 300Bse with a stacked SMPS as in my 845 so u get DRD , ok nothing new but shouold be interesting
Maybe i should start my own thread for this ?
So suggestions , welcome , next 2/3 months is the brainstorming time
On slight problem - you have semiconductors in the amp - so it's hybrid not tube; otherwise I like it.
Using a driver transformer if you can't find the right tube. That's what their job is - to supply current to loads like greedy grids.
I've also got an RCA 807 push pull modulator amp using 807 cathode drive that seems to work quite well. 6 tubes used in all. But a transformer would be another option.
As much as I like the amp you have - the minute I see semiconductors especially in the audio path, I call that cheating ! It's way too common these days.
If it sounds good (arguably better than the options you've suggested), what's wrong with taking the easy way utilizing modern technology?
If it's not your preference, than I understand that, but to call it cheating isn't really fair in my opinion. I think we're all after creating amplifiers that sound good to us, whether that's using a semiconductor or not.