capacitors
Hi Filip,
correct ! that's the ultra-parafeed cap. And yes: that is a high quality item. And worth investing some money !
Your questions:
- the anode choke is a 40 H device capable of 750 mA ! (and safe up till 8 kV). It's a double chamber design.
- the capacitor is a 4 uF / 4 kV item. And there is a lot to chose from (Ebay). But i've found out that some brands do sound pretty nice. Of course: that's purely objective and only true in MY set-up. That does not mean that there no alternatives. I've found Leclanche BOS-caps very good but difficult to source at higher uF-ratings. Then i found CSI. And i'm hooked to that brand. High quality, rather small given it's value and good sounding. See picture.
- sinking the cap value lower than 3 uF impaired the bass. Going higher than 5 uF was of no value. So it seems that given the opt-impendance 3 ~5 uF is a nice value to start. Which does only concurr with all the formulas by Paul Joppa and Lynn Olsen. I did their maths and came by following their theory to the same values.
Although you can find on Ebay and hamfests often enough nice value oil capacitors they are prone to leak. More modern are of a non-pcb variety (recommended). But PLEASE do check on leakage ! All the "bathtub"-items i would discard: they are sealed by a cork or phenolic washer. And that is by now seriously detiorated. Do you dare to put high voltage on those items ?
If you buy new paper-oil capacitors be prepared to pay serious money. The best thing is to check the hamfests and local army dumps. They are most of the time a real paper-oil-mine.
I've listened to the russian oil caps in power supplies. Good value for money ! but also here: there are differences in their quality. I personally would not use the PET-variety altough it has an amazing compact size for it's value. It simply did not sound correct. I never heared large value teflon caps. From the smaller signal size caps i do hear a lot of good support, so there must certainly be quality there. The largest value Russian teflon cap i saw was a 0,039 uF / 1000 V and a 0,047 uF / 8000 V. Hardly a powersupply cap and also too small for ultra-parafeed duties. Have you seen others ?
Included a picture of the used caps: a 25 uF / 3,5 kV in the power supply. And a 4 uF / 4 kV as ultra-parafeed cap.
(and i found a source of these caps.....if everything is going as planned i'm receiving a nice stash of 5 uF / 3,5 kV end of June)
Greetings from your Northern neighbour,
Reinout
Hi Filip,
correct ! that's the ultra-parafeed cap. And yes: that is a high quality item. And worth investing some money !
Your questions:
- the anode choke is a 40 H device capable of 750 mA ! (and safe up till 8 kV). It's a double chamber design.
- the capacitor is a 4 uF / 4 kV item. And there is a lot to chose from (Ebay). But i've found out that some brands do sound pretty nice. Of course: that's purely objective and only true in MY set-up. That does not mean that there no alternatives. I've found Leclanche BOS-caps very good but difficult to source at higher uF-ratings. Then i found CSI. And i'm hooked to that brand. High quality, rather small given it's value and good sounding. See picture.
- sinking the cap value lower than 3 uF impaired the bass. Going higher than 5 uF was of no value. So it seems that given the opt-impendance 3 ~5 uF is a nice value to start. Which does only concurr with all the formulas by Paul Joppa and Lynn Olsen. I did their maths and came by following their theory to the same values.
Although you can find on Ebay and hamfests often enough nice value oil capacitors they are prone to leak. More modern are of a non-pcb variety (recommended). But PLEASE do check on leakage ! All the "bathtub"-items i would discard: they are sealed by a cork or phenolic washer. And that is by now seriously detiorated. Do you dare to put high voltage on those items ?
If you buy new paper-oil capacitors be prepared to pay serious money. The best thing is to check the hamfests and local army dumps. They are most of the time a real paper-oil-mine.
I've listened to the russian oil caps in power supplies. Good value for money ! but also here: there are differences in their quality. I personally would not use the PET-variety altough it has an amazing compact size for it's value. It simply did not sound correct. I never heared large value teflon caps. From the smaller signal size caps i do hear a lot of good support, so there must certainly be quality there. The largest value Russian teflon cap i saw was a 0,039 uF / 1000 V and a 0,047 uF / 8000 V. Hardly a powersupply cap and also too small for ultra-parafeed duties. Have you seen others ?
Included a picture of the used caps: a 25 uF / 3,5 kV in the power supply. And a 4 uF / 4 kV as ultra-parafeed cap.
(and i found a source of these caps.....if everything is going as planned i'm receiving a nice stash of 5 uF / 3,5 kV end of June)
Greetings from your Northern neighbour,
Reinout
Attachments
anode choke
Hello Unison845,
i think you better talk to your transformer-winder. A 200 H / 200 mA choke. And safe/capable for give-ot-take a couple of kV's is certainly not a standard item. Maybe you can talk to NickC ? He mentioned prices for his transformers......transformer-heaven !
For my 833-high voltage line i used:
- E150 power transformer. With a couple of secondary taps (1000 - 1200 - 1400 V) and a couple of taps on the primary for finding the optimum (+ 5 % and + 10 %). Now i've found out that the actual voltage is not that critical. So with a new amp i would make this transformer more simple.
- E126 choke 10 H / 750 mA
- E150 anode choke. 40 H / 750 mA. Double chamber design. Yes....i know, that is way to much reserve on milliamperes. But i had to find out the experimental way because there is almost nobody that uses these items.
And when i had these items and they worked fine.....why not use them in an amp ?
In the picture:
- E150 power transformer in front;
- E125 choke left back;
- E150 anode choke right back;
And of course you have to keep those Tamura's. Dream-stuff ! Put them to good use.
Reinout
Hello Unison845,
i think you better talk to your transformer-winder. A 200 H / 200 mA choke. And safe/capable for give-ot-take a couple of kV's is certainly not a standard item. Maybe you can talk to NickC ? He mentioned prices for his transformers......transformer-heaven !
For my 833-high voltage line i used:
- E150 power transformer. With a couple of secondary taps (1000 - 1200 - 1400 V) and a couple of taps on the primary for finding the optimum (+ 5 % and + 10 %). Now i've found out that the actual voltage is not that critical. So with a new amp i would make this transformer more simple.
- E126 choke 10 H / 750 mA
- E150 anode choke. 40 H / 750 mA. Double chamber design. Yes....i know, that is way to much reserve on milliamperes. But i had to find out the experimental way because there is almost nobody that uses these items.
And when i had these items and they worked fine.....why not use them in an amp ?
In the picture:
- E150 power transformer in front;
- E125 choke left back;
- E150 anode choke right back;
And of course you have to keep those Tamura's. Dream-stuff ! Put them to good use.
Reinout
Attachments
CSI capacitor
Hello ReinoutdV,
Another coincidence???
Here is the CSI capacitor that I used for my 250TL. Unfortunately I did not use for my 833 due to chassis space. These are quite good caps, retail for $68 but they are worth it. A Japanese DIY that I know used this in his 300B like it very much.
Hello ReinoutdV,
Another coincidence???
Here is the CSI capacitor that I used for my 250TL. Unfortunately I did not use for my 833 due to chassis space. These are quite good caps, retail for $68 but they are worth it. A Japanese DIY that I know used this in his 300B like it very much.
items....in transit...
Hi Unison845,
my brother lives in the USA and evey year he's visiting me. When i buy items at Ebay i normally let them ship transatlantic, but sometimes sellers simply do not want to send soemthing transatlanic ?! So then i "use" my brother as a back-up plan. If everything goes well he'll take this time with him: a lot of high quality resistors, 6 very nice CSI-caps (5 uF / 3,5 kV),and even some NEW Johnson 833-tube sockets.
Now hope that everything goes allright.
The awaited caps. Very nice ultra(path)/parafeed caps indeed !
Reinout
Hi Unison845,
my brother lives in the USA and evey year he's visiting me. When i buy items at Ebay i normally let them ship transatlantic, but sometimes sellers simply do not want to send soemthing transatlanic ?! So then i "use" my brother as a back-up plan. If everything goes well he'll take this time with him: a lot of high quality resistors, 6 very nice CSI-caps (5 uF / 3,5 kV),and even some NEW Johnson 833-tube sockets.
Now hope that everything goes allright.
The awaited caps. Very nice ultra(path)/parafeed caps indeed !
Reinout
Attachments
Worlds most expensive amp !
I just received the latest issue of stereophile which has the 350,000$ !!! Wavac four chassis monoblocks.
Michael Fremer's review is over the top and he seems almost ready to sell his house to have them.
Of course the measurements were some of the worst possible.
I just received the latest issue of stereophile which has the 350,000$ !!! Wavac four chassis monoblocks.
Michael Fremer's review is over the top and he seems almost ready to sell his house to have them.
Of course the measurements were some of the worst possible.
Wavac SH-833
Hi Protos,
i read it......$350.000,00 is quite some more than i paid in total for my amps (+ rest of the audiosystem + car + + + ).
There are some similarities in "our" designs:
- seperate powersupply. OK, i do no have the isolation transformers. But almost all the tubes have their own designated powerlines with their own transformers/coils.
- the width / depth of the soundstage. That is one of THE striking things with these tubes.
Of course dissimilarities;
- price.......i honestly can't give you the exact amount of €'s that i spend. I had lots of items already "on the shelf". But is was less than 1/10 of the SH-833. It gives you an idea.
- i do not have the bass-bump. In fact the amps are really neutral. Quite non-tube: no cuddly warm low notes or fast roll of in the highs.
350.000........
It happens that i have some 833 sockets left. When i have more time i'll post it in this thread. They will not be cheap.......they were not cheap for me in the first place......but with a budget of 350.000-minus-minus-minus you will have a lot more fun making these amps by yourself and be proud of your own accomplishment. And besides the good sound isn't that why we are doing our audio-thing ?
By the way: after some months with the Amperex 833 i found out that there was no real difference with the Tungsram's OT400. So tube wise i'm looking for really different construction/builded tubes:
- originals:
With regards,
Reinout
By the wa
Hi Protos,
i read it......$350.000,00 is quite some more than i paid in total for my amps (+ rest of the audiosystem + car + + + ).
There are some similarities in "our" designs:
- seperate powersupply. OK, i do no have the isolation transformers. But almost all the tubes have their own designated powerlines with their own transformers/coils.
- the width / depth of the soundstage. That is one of THE striking things with these tubes.
Of course dissimilarities;
- price.......i honestly can't give you the exact amount of €'s that i spend. I had lots of items already "on the shelf". But is was less than 1/10 of the SH-833. It gives you an idea.
- i do not have the bass-bump. In fact the amps are really neutral. Quite non-tube: no cuddly warm low notes or fast roll of in the highs.
350.000........
It happens that i have some 833 sockets left. When i have more time i'll post it in this thread. They will not be cheap.......they were not cheap for me in the first place......but with a budget of 350.000-minus-minus-minus you will have a lot more fun making these amps by yourself and be proud of your own accomplishment. And besides the good sound isn't that why we are doing our audio-thing ?
By the way: after some months with the Amperex 833 i found out that there was no real difference with the Tungsram's OT400. So tube wise i'm looking for really different construction/builded tubes:
- originals:
With regards,
Reinout
By the wa
Wavac SH-833 2
Hi again Protos,
to fast with typing....hit the button and the reply was already underway !
To continue:
- originals: metal plate, plate fixed to the anode topconnector. Examples RCA, Tungsram OT400, GE, Westinghouse. NOS-stuff !
- modern: carbon plate.
- funny ones: metal plate, but really different plate structure or tube construction. Examples: ES833, Polyaron GU-48, LR833. I've attached a picture of the LR833. It's a Swedish 833 equivalent. Now try to score a pair of them ! Never heared them....but i know they exist.
With regards,
Reinout
Hi again Protos,
to fast with typing....hit the button and the reply was already underway !
To continue:
- originals: metal plate, plate fixed to the anode topconnector. Examples RCA, Tungsram OT400, GE, Westinghouse. NOS-stuff !
- modern: carbon plate.
- funny ones: metal plate, but really different plate structure or tube construction. Examples: ES833, Polyaron GU-48, LR833. I've attached a picture of the LR833. It's a Swedish 833 equivalent. Now try to score a pair of them ! Never heared them....but i know they exist.
With regards,
Reinout
Attachments
833A SE amps
I just found this forum by doing an Ask Jeeves search for 833A. I had thought that I was the only one crazy enough to DIY an audio amp with this tube. I have been building audio amps (tube and SS) for 40+ years.
All of my efforts for the past two years (mostly tube and hybrid) are chronicled on my web site. www.tubelab.com
I have come up with a unique driver approach to deal with the grid current found in A2 opeation. I use a constant current source IC to load the driver triode connected to a mosfet source follower to provide grid drive. This allows me to use a DHT to drive a transmiting tube without the usual limitations. This amp will put out over 200 watts RMS at 5% distortion. Distortion at 75 Watts is under 1%.
My 833A amp prototype is cobbled together to test a prototype output transformer. It uses my 845 SE amp with an external power supply, tube and transformer. I am using a 45 as the driver tube and a 5842 as the input tube. The schematic diagram is the same as the 845SE amp which is posted on the web site.
For information on this driver circuit see the PowerDrive page.
A first look at the picture will evoke the notion that I am crazy (partially true) and practicing unsafe electricity. Understand that I was across the room when this was powered up. A thick sheet of Lexan seperated me from the unit, and I had a fire extinguisher and kill switch nearby.
There are safety and safe practices pages on the site which should be of interest to newcommers to the world of vacuum tube electronics.
Feel free to use any of my designs for non-commercial use. The site will be receiving a makeover in the coming months, since it has become somewhat disorganized.
I just found this forum by doing an Ask Jeeves search for 833A. I had thought that I was the only one crazy enough to DIY an audio amp with this tube. I have been building audio amps (tube and SS) for 40+ years.
All of my efforts for the past two years (mostly tube and hybrid) are chronicled on my web site. www.tubelab.com
I have come up with a unique driver approach to deal with the grid current found in A2 opeation. I use a constant current source IC to load the driver triode connected to a mosfet source follower to provide grid drive. This allows me to use a DHT to drive a transmiting tube without the usual limitations. This amp will put out over 200 watts RMS at 5% distortion. Distortion at 75 Watts is under 1%.
My 833A amp prototype is cobbled together to test a prototype output transformer. It uses my 845 SE amp with an external power supply, tube and transformer. I am using a 45 as the driver tube and a 5842 as the input tube. The schematic diagram is the same as the 845SE amp which is posted on the web site.
For information on this driver circuit see the PowerDrive page.
A first look at the picture will evoke the notion that I am crazy (partially true) and practicing unsafe electricity. Understand that I was across the room when this was powered up. A thick sheet of Lexan seperated me from the unit, and I had a fire extinguisher and kill switch nearby.
There are safety and safe practices pages on the site which should be of interest to newcommers to the world of vacuum tube electronics.
Feel free to use any of my designs for non-commercial use. The site will be receiving a makeover in the coming months, since it has become somewhat disorganized.
SE amps with 833A or bigger tubes
I have four 5867 tubes with sockets and chimneys. I will try one of them in this test amp in search of more power and better high frequency response. I have found only sparse data on this tube but it seems to be similar to the 3-500Z. I agree that a 450TL is probably the best looking tube of the bunch. I thought about trying to make a SE audio amp with the 4PR1000's that I had, but when I got the prices for transformers I sold the tubes on Ebay to pay for the transformers for the 833A.
I have four 5867 tubes with sockets and chimneys. I will try one of them in this test amp in search of more power and better high frequency response. I have found only sparse data on this tube but it seems to be similar to the 3-500Z. I agree that a 450TL is probably the best looking tube of the bunch. I thought about trying to make a SE audio amp with the 4PR1000's that I had, but when I got the prices for transformers I sold the tubes on Ebay to pay for the transformers for the 833A.
Mosfet drive for 833A or other SE triode
I have done exactly that and it works excellent. The schematic and theory is on my web site. The 833A amp uses the same schematic as the 845SE which is on the site (www.tubelab.com/845SE.htm).
I spent several months figuring out the best way to drive a large tube that draws grid current. I tried cathode followers, transformers, bipolar transistors and mosfets. The mosfets work the best, especially when paired with a constant current source IC for loading the driver tube. The results of all of this work is presented (with schematics) on the Powerdrive page. www.tubelab.com/powerdrive.htm
I know that many tubeheads are sandophobic (fear of silicon) but I have been using this circuit to drive everything from 45's to 833A's with great success. It sounds great, gives flat phase and frequency response out to 300KHz, while driving the grid of an 833A to +100 volts. Distortion on my 833A prototype is below 1% at 75 watts and rises to 4% at 212 watts RMS. Show me a driver transformer that can do that. The mosfet to use is a 2SK2700 available from DigiKey in the US.
I have done exactly that and it works excellent. The schematic and theory is on my web site. The 833A amp uses the same schematic as the 845SE which is on the site (www.tubelab.com/845SE.htm).
I spent several months figuring out the best way to drive a large tube that draws grid current. I tried cathode followers, transformers, bipolar transistors and mosfets. The mosfets work the best, especially when paired with a constant current source IC for loading the driver tube. The results of all of this work is presented (with schematics) on the Powerdrive page. www.tubelab.com/powerdrive.htm
I know that many tubeheads are sandophobic (fear of silicon) but I have been using this circuit to drive everything from 45's to 833A's with great success. It sounds great, gives flat phase and frequency response out to 300KHz, while driving the grid of an 833A to +100 volts. Distortion on my 833A prototype is below 1% at 75 watts and rises to 4% at 212 watts RMS. Show me a driver transformer that can do that. The mosfet to use is a 2SK2700 available from DigiKey in the US.
Attachments
833A output transformer
I had the transformer custom made. I don't know yet whether we (Tubelab) will offer this transformer for sale or if the manfufacturer wants to deal with direct sales. I will keep the 833A page updated with the transformer information as they become available. I think it may be a month or two before the details are worked out.
I had the transformer custom made. I don't know yet whether we (Tubelab) will offer this transformer for sale or if the manfufacturer wants to deal with direct sales. I will keep the 833A page updated with the transformer information as they become available. I think it may be a month or two before the details are worked out.
833A guitar amp!
I assembled a single channel prototype 833A amplifier for the purpose of evaluating a prototype output transformer. I performed all of the usual testing on this amp, which led to the conclusion that I will build a complete stereo amplifier using 833A tubes at a later date.
One of the other conclusions was that my PowerDrive circuit was capable driving an 833A flawlessly out to at least 300KHz in A2 operation. Grid current was estimated to exceed 100mA on peaks.
In a moment of insanity I connected my guitar preamp up to the 833A amp. I was not expected for what I found. This thing sounded awesome. I think that it was the best sounding guitar amp that I have ever built. It sounded so good that I want to build one.
The details and pictures can be found at www.tubelab.com/833SE.htm
I assembled a single channel prototype 833A amplifier for the purpose of evaluating a prototype output transformer. I performed all of the usual testing on this amp, which led to the conclusion that I will build a complete stereo amplifier using 833A tubes at a later date.
One of the other conclusions was that my PowerDrive circuit was capable driving an 833A flawlessly out to at least 300KHz in A2 operation. Grid current was estimated to exceed 100mA on peaks.
In a moment of insanity I connected my guitar preamp up to the 833A amp. I was not expected for what I found. This thing sounded awesome. I think that it was the best sounding guitar amp that I have ever built. It sounded so good that I want to build one.
The details and pictures can be found at www.tubelab.com/833SE.htm
Re: if audio fails.... (1)
Reinout,
You 'found' my 833A magnifier Tesla coil pictures. http://www.diyaudio.com/forums/showthread.php?s=&threadid=24424&perpage=10&pagenumber=14
The 833A is being run as a self excited class-C power oscillator (common configuration fr undustrial RF heating sources). It has about 4 kV on the plate with a power input to the tube of about 1.5 kW as shown in the photo. The high voltage brush discharge is striking a grounded sheet metal target above th discharge pin terminal 22" airgap.
I actually made a much more powerful vac tube TC employing three EEV, 5 kW PD transmitting triodes in parallel which I dubbed the "Coronatron". The picture is the lab guiney pig with a 1000 watt clear incandescent filament light bulb in his mouth standing near the operating Coronatron at barely above idle. The link gives more explanation.
http://www.area31.org/uncfestr.html
This has been a very interesting thread. I stopped reading at your post on page 14 where I found two familiar photos and plan to resume my reading shortly.
I note interest in the Eimac 450 series triodes. I have four of the 450TH's and am giving serious consideration to throwing together a P-P subwoofer amplifier with two of them and a 150 watt/ch dual mono SET with the other two. It has been quite a while since I built something that processes a fair bit of power using thermionic valves so with my interest in tube audio, this ought to be quite fun. For the sub amp I was thinking of using a nice big dry Hammond plate xfmr I have that is good for about 2 kW at 60 Hz CCS as the P-P output iron. It weighs about 100 lbs. Based on turns ratio it should give me a 7k plate to plate Z with an 8 ohm load on the 120 volt primary. Must go measure the L on this beast today and dolly it over to the lab where I can measure it's frequency response. I'll concentrate on the P-P amp first as it is the one with easier frequency response demands and is the more radical (read potentially fun) project of the two.
ReinoutdV said:
Reinout,
You 'found' my 833A magnifier Tesla coil pictures. http://www.diyaudio.com/forums/showthread.php?s=&threadid=24424&perpage=10&pagenumber=14
The 833A is being run as a self excited class-C power oscillator (common configuration fr undustrial RF heating sources). It has about 4 kV on the plate with a power input to the tube of about 1.5 kW as shown in the photo. The high voltage brush discharge is striking a grounded sheet metal target above th discharge pin terminal 22" airgap.
I actually made a much more powerful vac tube TC employing three EEV, 5 kW PD transmitting triodes in parallel which I dubbed the "Coronatron". The picture is the lab guiney pig with a 1000 watt clear incandescent filament light bulb in his mouth standing near the operating Coronatron at barely above idle. The link gives more explanation.
http://www.area31.org/uncfestr.html
This has been a very interesting thread. I stopped reading at your post on page 14 where I found two familiar photos and plan to resume my reading shortly.
I note interest in the Eimac 450 series triodes. I have four of the 450TH's and am giving serious consideration to throwing together a P-P subwoofer amplifier with two of them and a 150 watt/ch dual mono SET with the other two. It has been quite a while since I built something that processes a fair bit of power using thermionic valves so with my interest in tube audio, this ought to be quite fun. For the sub amp I was thinking of using a nice big dry Hammond plate xfmr I have that is good for about 2 kW at 60 Hz CCS as the P-P output iron. It weighs about 100 lbs. Based on turns ratio it should give me a 7k plate to plate Z with an 8 ohm load on the 120 volt primary. Must go measure the L on this beast today and dolly it over to the lab where I can measure it's frequency response. I'll concentrate on the P-P amp first as it is the one with easier frequency response demands and is the more radical (read potentially fun) project of the two.
