When you say "challenge the 45 stage", did you intend to say "change the 45 stage"? What do you mean by "challenge"?
Forget my comment...I was under the impression you wanted to use this as a line stage...its actually meant as your power amp, I see...
well...I cant comment on taste regarding endtriodes. I did not try the 45, I started with the El34 in triode, 300B, many different types including Eml Mesh, Eml520, went to Kr842, kr t-100, many different 845 incl. Elrog Normal and Molybd., 813 and finally Gm70 in its different versions.
I found that most of the time I am listening to 8W actually, even with the big ones when you look at the max. level of the recordings and what the real Vpp is you present to your speakers. Nevertheless, the more power on the heater, and especially the realismn of thoriated tungsten filament vs. oxide, the better for me.
I like as well the higher mu of the 813/gm70...this fits nicely to the 801a which drives them...and 2k as rp is still giving you great OPTs.
If you want a budget version of this with max sound quality, get a pair of philips 814 in triode mode. Easily en par with the best 845 i have here and a pair is oftenly 60 to 80 Euro NOS...As well rp of around 2k. But much better than 300B.
And if you want to invest into expensive iron...I would invest into the end game. Which is more like a 8k to 10 k OPT...Nano...from Alexander (which he is winding for me as we write...maybe he want to post pictures when they are done)...which you could use even for a nice 801A end stage if you want lower power (but the 814 is cheaper, has more power on the heater 10v, 3A, a lower rp of 2k, a similar mu of 8 etc. its really a super tube and plays from 600V to 900V or more happily. Those guys from Aries Cerat are not completely stupid...they know their stuff as well..Ale and others reported about the 814 equally.) But it needs to be the Philips version 814A version, which is build like a tank...and it will be for sure equal or better than most of the current production stuff, no matter how big the name is...save the money on the tubes and spend it for the very best iron instead.
well...I cant comment on taste regarding endtriodes. I did not try the 45, I started with the El34 in triode, 300B, many different types including Eml Mesh, Eml520, went to Kr842, kr t-100, many different 845 incl. Elrog Normal and Molybd., 813 and finally Gm70 in its different versions.
I found that most of the time I am listening to 8W actually, even with the big ones when you look at the max. level of the recordings and what the real Vpp is you present to your speakers. Nevertheless, the more power on the heater, and especially the realismn of thoriated tungsten filament vs. oxide, the better for me.
I like as well the higher mu of the 813/gm70...this fits nicely to the 801a which drives them...and 2k as rp is still giving you great OPTs.
If you want a budget version of this with max sound quality, get a pair of philips 814 in triode mode. Easily en par with the best 845 i have here and a pair is oftenly 60 to 80 Euro NOS...As well rp of around 2k. But much better than 300B.
And if you want to invest into expensive iron...I would invest into the end game. Which is more like a 8k to 10 k OPT...Nano...from Alexander (which he is winding for me as we write...maybe he want to post pictures when they are done)...which you could use even for a nice 801A end stage if you want lower power (but the 814 is cheaper, has more power on the heater 10v, 3A, a lower rp of 2k, a similar mu of 8 etc. its really a super tube and plays from 600V to 900V or more happily. Those guys from Aries Cerat are not completely stupid...they know their stuff as well..Ale and others reported about the 814 equally.) But it needs to be the Philips version 814A version, which is build like a tank...and it will be for sure equal or better than most of the current production stuff, no matter how big the name is...save the money on the tubes and spend it for the very best iron instead.
Last edited:
banpuku - my advice from last week was to rewire your present psu caps, but the reply from member 50AE was better: use smaller LC stages. The Kemet 550µF is much too big and slow in impulse response for a Single Ended amp. (For PushPull-AB it is good)
Your psu caps: Wima dc link - lean bass, grey plastic tone. Russian pio - slow, warm tone. But i may be complete wrong, as some insist that caps have no sound.
You want to use amorphous or nanocrystalline C-core chokes with ultra low DCR - try it. As long you use the same psu caps as now + the slow 50µF russ. pio cathode caps on 45B, you will not have the improvement you are hoping for.
Smaller LC stages: to find the right ballance for good sound is try and error. Use in your psu for C1 and C2 values from 50µF-100µF. (circa values - you may try 0.1 bypass) At these values impulse response is fast and AC rest-ripple will not be too high. Last week i said: with C1 10µF you have 10 Volt AC rest-ripple - too high for a SE amp.
Cap type: I use as compromise electrolytics with 0,1 Film bypass. Member Blitz said the CDE 947D are the best sounding psu caps he has tried. They are used in the super expensive Aries Cerat tube amps.
You can't compensate the flaws of your present psu caps. I hope the psu changes will result in better sound, but 4 Watt are still very weak ....
Connect the EML 45B to C1 and the C3g to C2 psu.
A few years ago i had a ECC40 dc coupled 45 SE amp (at 7W bias) with LCLC psu: first L=155 Ohm, sec. L=200 Ohm, C1,C2=100µF. I had stunning dynamics on 98db loudspeakers and decent bass with 1 Watt SE.
You have 51 Ohm chokes - for me these are low dcr.
Member euro21 gave you the advice to try the 4 Ohm tap. How is it ?
You need only a new high Volt psu + DC filament and a pair of 300B-XLS to rebuild the 45B to a powerfull 13 Watt SE amp.
Your psu caps: Wima dc link - lean bass, grey plastic tone. Russian pio - slow, warm tone. But i may be complete wrong, as some insist that caps have no sound.
You want to use amorphous or nanocrystalline C-core chokes with ultra low DCR - try it. As long you use the same psu caps as now + the slow 50µF russ. pio cathode caps on 45B, you will not have the improvement you are hoping for.
Smaller LC stages: to find the right ballance for good sound is try and error. Use in your psu for C1 and C2 values from 50µF-100µF. (circa values - you may try 0.1 bypass) At these values impulse response is fast and AC rest-ripple will not be too high. Last week i said: with C1 10µF you have 10 Volt AC rest-ripple - too high for a SE amp.
Cap type: I use as compromise electrolytics with 0,1 Film bypass. Member Blitz said the CDE 947D are the best sounding psu caps he has tried. They are used in the super expensive Aries Cerat tube amps.
You can't compensate the flaws of your present psu caps. I hope the psu changes will result in better sound, but 4 Watt are still very weak ....
Connect the EML 45B to C1 and the C3g to C2 psu.
A few years ago i had a ECC40 dc coupled 45 SE amp (at 7W bias) with LCLC psu: first L=155 Ohm, sec. L=200 Ohm, C1,C2=100µF. I had stunning dynamics on 98db loudspeakers and decent bass with 1 Watt SE.
You have 51 Ohm chokes - for me these are low dcr.
Member euro21 gave you the advice to try the 4 Ohm tap. How is it ?
You need only a new high Volt psu + DC filament and a pair of 300B-XLS to rebuild the 45B to a powerfull 13 Watt SE amp.
banpuku - sorry i made a mistake in post 103:
Do not wire tube C3g direct to C2 cap - the voltage is much too high there. I wanted to write to C3, as in your schematic.
Use for C3 a better cap type.
Connect resistor 11K to C1 and listen, swap back to C2 and choose the better sounding one.
Do not wire tube C3g direct to C2 cap - the voltage is much too high there. I wanted to write to C3, as in your schematic.
Use for C3 a better cap type.
Connect resistor 11K to C1 and listen, swap back to C2 and choose the better sounding one.
I think we are making a similar point...the cost to build a 814 14W SE amp might be the same as the planned 45EML version and much cheaper than a 300bxls (which is comparable to the Kr842, but the Kron is better). Its all about headroom for dynamics. Most of the time you ll listen maybe to 3-4 Watt, but when you need dynamics, they are there in such a natural, easy way that you are shocked about the realismn.
And if you have the desire, you could still use later 845 or gm70...but I doubt that. The 60W dissipation of the 814 is well above the 300B and en par with the Kr842/300bxls, but you got a thoriated tungsten filament as strong as the 845. And that is a game changer like using amorphous or nano chokes.
After gone through all of this, I cant understand the 300B hype...the only advantage there is that you have lower HV...but, well, the CDE 947D start with min. 900VDC spec anyhow...the real costs begin when you buy iron which you dont use later anymore because you kniw better.
And if you have the desire, you could still use later 845 or gm70...but I doubt that. The 60W dissipation of the 814 is well above the 300B and en par with the Kr842/300bxls, but you got a thoriated tungsten filament as strong as the 845. And that is a game changer like using amorphous or nano chokes.
After gone through all of this, I cant understand the 300B hype...the only advantage there is that you have lower HV...but, well, the CDE 947D start with min. 900VDC spec anyhow...the real costs begin when you buy iron which you dont use later anymore because you kniw better.
Nice to come back to the original question.
The supply is well designed for the purpose, the 500Vrms means the rectifier puts out 680V peak losses already considered.
Simul with the available data. when switching on.
the first choke reduces the voltage by 250V, so not possible to reduce the 10H. It outputs a ripple of 11Vpp mainly 120Hz
the second choke reduces the ripple to 41mVpp
The supply is well designed for the purpose, the 500Vrms means the rectifier puts out 680V peak losses already considered.
Simul with the available data. when switching on.
the first choke reduces the voltage by 250V, so not possible to reduce the 10H. It outputs a ripple of 11Vpp mainly 120Hz
the second choke reduces the ripple to 41mVpp
Last edited:
Well,
The critcal inductance of a 410V/60mA choke-input supply is at 6H I believe. If you sink additional 10-15mA in a bleeder resistor you can go actually down to 5H. 50 Ohm is a bit on the high side for me personally, I would like to see something between 20-30 Ohm.
To the snap-question of this design:
- 866 vs 83 will bring a lot of snap and musicality. Different animal.
- Give the 45 a real fixed bias through the secondary of the IT and get rid of the Caps in the signal path all together.
- Get rid of the resistor pair at the cathode. Musical energy / snap destroyer. Allow a nicely passively filtered DC-supply for the 45 instead (idealy with a LT4320 and Nichicon Superthrough and some amorphous chokes from Alexander with max 0,2ohm rdc)
The critcal inductance of a 410V/60mA choke-input supply is at 6H I believe. If you sink additional 10-15mA in a bleeder resistor you can go actually down to 5H. 50 Ohm is a bit on the high side for me personally, I would like to see something between 20-30 Ohm.
To the snap-question of this design:
- 866 vs 83 will bring a lot of snap and musicality. Different animal.
- Give the 45 a real fixed bias through the secondary of the IT and get rid of the Caps in the signal path all together.
- Get rid of the resistor pair at the cathode. Musical energy / snap destroyer. Allow a nicely passively filtered DC-supply for the 45 instead (idealy with a LT4320 and Nichicon Superthrough and some amorphous chokes from Alexander with max 0,2ohm rdc)
"many times better" is meaningless.
I presume you have never tried "swinging chokes" (eg. UTC) because nobody now makes any.
LS series UTC stuff is like partridge.
Did you ever test partridge or UTC - LS range or even Sowter/Carnhill?
I doubt it.
Blitz - banpuku is using this amp since more than 2 years. He is not happy with the sound. He is using the standard Hi-B Monolith S-11 opt, not the nanocrystalline SX-11 in the schematic. He has a power hungry 87 db Loudspeaker with a 4 Ohm impedance dip. Read my post 58 on page 6 of this thread for this. We only know that 4 Watt from his SE 45B is to weak for his loudspeakers.
I know the EML 300b-XLS and 520B. If you say the KR842 sounds better - i believe you, you have a ton of experience more than i. His Monolith 5K opt is a good starting point. The KR842 would be a good match. With the big Tungsten transmitting tubes there is the heath problem - at high power they are extreme heat radiators. We don't know if banpuku lives in south or north of USA and how big his music room is. The bright filament transmitting tubes are cheaper and sound more powerfull than the red glowing Bariumoxide filament tubes. The KR842 has 9 Watt filament, the transmitting tubes have ca 31 - 33 Watt hot filament.
Transmitting tubes: at low-medium ca 40 watt bias the heat should not be so extreme. But i have no diy experience with transmitting tubes.
I don't know if banpuku's skills are safe for 1000VDC.
I know the EML 300b-XLS and 520B. If you say the KR842 sounds better - i believe you, you have a ton of experience more than i. His Monolith 5K opt is a good starting point. The KR842 would be a good match. With the big Tungsten transmitting tubes there is the heath problem - at high power they are extreme heat radiators. We don't know if banpuku lives in south or north of USA and how big his music room is. The bright filament transmitting tubes are cheaper and sound more powerfull than the red glowing Bariumoxide filament tubes. The KR842 has 9 Watt filament, the transmitting tubes have ca 31 - 33 Watt hot filament.
Transmitting tubes: at low-medium ca 40 watt bias the heat should not be so extreme. But i have no diy experience with transmitting tubes.
I don't know if banpuku's skills are safe for 1000VDC.
Blitz - I learned about 50 posts ago that sarcastic1's comments are meaningless. Just ignore his rants.
Now, to the task at hand. I did some part swapping this morning and tried some of the suggestions.
1. Taking B+ to the OPT from C1 causes too much hum.
2. The Russian PIO 50uF cathode bypass cap was replaced with a Jantzen Superior Z-cap (only 5.6uF). This improved the "live" factor, a bit more snap. But, to your point in post 107, let's eliminate completely the need for a cap. So, I will try fixed bias.
3. The 500uF Kemet C2 cap is much better without the Russian PIO 50uF bypass C2 cap. So, for now, I am running C2 with the 500uF Kemet. That said, I am interested in other opinions on the Cornell Dubilier 947D Series Film Capacitors in the C2 position. The smallest 947D caps are 130uF.
More to come.
Now, to the task at hand. I did some part swapping this morning and tried some of the suggestions.
1. Taking B+ to the OPT from C1 causes too much hum.
2. The Russian PIO 50uF cathode bypass cap was replaced with a Jantzen Superior Z-cap (only 5.6uF). This improved the "live" factor, a bit more snap. But, to your point in post 107, let's eliminate completely the need for a cap. So, I will try fixed bias.
3. The 500uF Kemet C2 cap is much better without the Russian PIO 50uF bypass C2 cap. So, for now, I am running C2 with the 500uF Kemet. That said, I am interested in other opinions on the Cornell Dubilier 947D Series Film Capacitors in the C2 position. The smallest 947D caps are 130uF.
More to come.
Hi Lauscher and Blitz- a couple of follow up points:
1. I am using the SX-11 nano-crystalline Monolith OPT. This is confirmed. I can send photos if you want.
2. I have built an AA drives GM70 amp before. Unfortunately, or actually very fortunately, I survived a 600V electrical shock when I accidentally touched B+. This literally took me down for 1 week as my body was not the same for quite some time. At that point, I decided to go lower voltage. Otherwise, I would have stayed with the GM70. Trust me, you don't want to get shocked with 600V+. I am lucky to be alive. Thank God!
3. If I go with different tubes/schematic, I want to utilize my existing SX-11 Monolith OPT, unless someone wants to purchase it? Hint Hint, then I could consider getting a new one.
4. One of my 83 rectifiers blew recently, so now I am using 5Z3 rectifiers. The 83 is much better than the 5Z3. That said, I am willing to try different rectifiers that are better than both the 83 and 5Z3. I used the 866 rectifiers with my GM70 amp, but space for half-wave rectifiers might be an issue, so I would prefer a full wave rectifier. Any thoughts on "best" full wave rectifiers that you like? Also, I do like mercury.
5. I don't mind the high heat tubes, as 70% of the time this is not a problem.
1. I am using the SX-11 nano-crystalline Monolith OPT. This is confirmed. I can send photos if you want.
2. I have built an AA drives GM70 amp before. Unfortunately, or actually very fortunately, I survived a 600V electrical shock when I accidentally touched B+. This literally took me down for 1 week as my body was not the same for quite some time. At that point, I decided to go lower voltage. Otherwise, I would have stayed with the GM70. Trust me, you don't want to get shocked with 600V+. I am lucky to be alive. Thank God!
3. If I go with different tubes/schematic, I want to utilize my existing SX-11 Monolith OPT, unless someone wants to purchase it? Hint Hint, then I could consider getting a new one.
4. One of my 83 rectifiers blew recently, so now I am using 5Z3 rectifiers. The 83 is much better than the 5Z3. That said, I am willing to try different rectifiers that are better than both the 83 and 5Z3. I used the 866 rectifiers with my GM70 amp, but space for half-wave rectifiers might be an issue, so I would prefer a full wave rectifier. Any thoughts on "best" full wave rectifiers that you like? Also, I do like mercury.
5. I don't mind the high heat tubes, as 70% of the time this is not a problem.
Attachments
Last edited by a moderator:
Have you measure the impedance of your speaker ? Its pretty simple with REW. What is the result ? The SX-11 is a 5k OPT with 4 and 8 ohm taps. Depending on your speaker, we ll see what the real primary impedance you can have with either tap. This gives a lot of flexibility on output tubes (e.g. when your speaker is 6 ohm).
By the way: My curent Nano OPT from Alexander was as well only a 300B unit Watt wise. I could connect the secondary windindings differently and came from 4k to 7k5 with my 6 ohm speaker. I ran all the tubes mentioned above with this one unit...and was always wondering why I could not realize that the OPT came to its power limits. Bass was always powerful etc. Than I found that the peak passages of my loudest recordings are recorded with -9db ! So, when I simulated I simulated always with 0db entry signal, but all the numbers change when your entry signal is only max -9db ! So, my (in theory) 20W GM70/845/813-setup never went higher than maybe 7-10W !!! So, your 10W SX-11 might be perfect capable for the bigger tube game as well. From the low voltage series its hard to beat the Kron 842...yes only 9 Watt on the heater, but thats 50% more than a 300B...and 2.5 times more than a 45. The T-100 is nice as well, different, mor adult and laid back character than the 842 which is more transparent and more dynamic. 842VHD=Very High Dynamic is not a wrong description.
Well, I am not aware of great sounding FW-Mercury-Rectifier. I love my Telefunken rgn2004 and 4004 rectifiers for their cool Mesh-Look and their very special, spacious sound. They have a different character than mercury, they are not as stiff, but you can try for small money AZ1/rgn1064 Telefunken MESH to understand how delicate they sound and what they do for you. NOrmally around 30 Euro. I use them for driver tubes (801A) and prefer them there above Mercury. For power tubes, you want it stiff. A good sounding 5u4g...for small money the black 5c3s from russia from the 50s. but the sky is the limit with these types...you can as well pay 500 Euro for EML and Kron and higher for Elrog...
I am running 950V, but I have bleeders everywhere which discharge the PSU when its turned off. I never touch anything in the first 15 min after power off, measure always the HV first before I start to work on the unit etc. The fear alone makes me much much more respectful as I know as well how 450V feels like...no, that hurts as well, my friend...tounching 450 V is not an option either...but once you got shocked: Its like driving a fast car. The faster my cars became, the more careful I drove as you loose control otherwise without realizising it...and consequences are deadly...actually I am now driving much slower than I used to.
I had some 500Uf DC-Link Kemet here as well...they are a nice entry drug. The CDE is better though, but the CDE needs as well one week of burn in. I am not surprised that the PIO sounds not good in parallel. I am using the CDE for C1 and C2.
By the way: My curent Nano OPT from Alexander was as well only a 300B unit Watt wise. I could connect the secondary windindings differently and came from 4k to 7k5 with my 6 ohm speaker. I ran all the tubes mentioned above with this one unit...and was always wondering why I could not realize that the OPT came to its power limits. Bass was always powerful etc. Than I found that the peak passages of my loudest recordings are recorded with -9db ! So, when I simulated I simulated always with 0db entry signal, but all the numbers change when your entry signal is only max -9db ! So, my (in theory) 20W GM70/845/813-setup never went higher than maybe 7-10W !!! So, your 10W SX-11 might be perfect capable for the bigger tube game as well. From the low voltage series its hard to beat the Kron 842...yes only 9 Watt on the heater, but thats 50% more than a 300B...and 2.5 times more than a 45. The T-100 is nice as well, different, mor adult and laid back character than the 842 which is more transparent and more dynamic. 842VHD=Very High Dynamic is not a wrong description.
Well, I am not aware of great sounding FW-Mercury-Rectifier. I love my Telefunken rgn2004 and 4004 rectifiers for their cool Mesh-Look and their very special, spacious sound. They have a different character than mercury, they are not as stiff, but you can try for small money AZ1/rgn1064 Telefunken MESH to understand how delicate they sound and what they do for you. NOrmally around 30 Euro. I use them for driver tubes (801A) and prefer them there above Mercury. For power tubes, you want it stiff. A good sounding 5u4g...for small money the black 5c3s from russia from the 50s. but the sky is the limit with these types...you can as well pay 500 Euro for EML and Kron and higher for Elrog...
I am running 950V, but I have bleeders everywhere which discharge the PSU when its turned off. I never touch anything in the first 15 min after power off, measure always the HV first before I start to work on the unit etc. The fear alone makes me much much more respectful as I know as well how 450V feels like...no, that hurts as well, my friend...tounching 450 V is not an option either...but once you got shocked: Its like driving a fast car. The faster my cars became, the more careful I drove as you loose control otherwise without realizising it...and consequences are deadly...actually I am now driving much slower than I used to.
I had some 500Uf DC-Link Kemet here as well...they are a nice entry drug. The CDE is better though, but the CDE needs as well one week of burn in. I am not surprised that the PIO sounds not good in parallel. I am using the CDE for C1 and C2.
Last edited:
Yes High Volt DC is extreme painfull and lethal.
In past you had several threads abouth your SE 45 amp, i had the wrong info that you use the S-11 ....
Do you know how to use the 83 mercury rectifier ? You need a separate switch for the 83 filament. First switch on the 83 filament, wait 2 minutes, then you can switch on the high Volt B+. You can use it only with LC input psu. First use after years of storage: Heat 2 hours only filament. Then switch of and wait a half day. After this you can can use with 2 minutes preheating. Are you preheating the 45B filaments ? ca 1-2 minutes before B+. Also wait ca 15 minutes after B+, before you play music. Tubes will live longer.
The Monolith SX-11 is build for high bias 300B-XLS = 100mA. I don't know why Monolith writes 80mA in the specs. The 80mA specs are from the S-9 with smaller airgap. Ask Monolith about this, the SX-11 specs may be wrong.
The SX-11 is good, keep it. First built a good sounding amp and then you can upgrade opt. The SX-11 is perfect for KR842. It should have ca 13 Watt at 450V/40Watt. To get decent power from 845, 814A you need high voltage. They match better with 7-8K opt. Blitz has experience with transmitting tubes.
First buy a few CDE 947D caps and try what i suggested for your psu. I will order 2 x 130µF CDE for my own 300B psu to try.
Then decide what future power tube you want.
In past you had several threads abouth your SE 45 amp, i had the wrong info that you use the S-11 ....
Do you know how to use the 83 mercury rectifier ? You need a separate switch for the 83 filament. First switch on the 83 filament, wait 2 minutes, then you can switch on the high Volt B+. You can use it only with LC input psu. First use after years of storage: Heat 2 hours only filament. Then switch of and wait a half day. After this you can can use with 2 minutes preheating. Are you preheating the 45B filaments ? ca 1-2 minutes before B+. Also wait ca 15 minutes after B+, before you play music. Tubes will live longer.
The Monolith SX-11 is build for high bias 300B-XLS = 100mA. I don't know why Monolith writes 80mA in the specs. The 80mA specs are from the S-9 with smaller airgap. Ask Monolith about this, the SX-11 specs may be wrong.
The SX-11 is good, keep it. First built a good sounding amp and then you can upgrade opt. The SX-11 is perfect for KR842. It should have ca 13 Watt at 450V/40Watt. To get decent power from 845, 814A you need high voltage. They match better with 7-8K opt. Blitz has experience with transmitting tubes.
First buy a few CDE 947D caps and try what i suggested for your psu. I will order 2 x 130µF CDE for my own 300B psu to try.
Then decide what future power tube you want.
A very simple, maybe very audible improvement is to try a small 0.47uF before the first choke...it should not increase HV, than 0,47 is too high. But you will notice a nice effect where the strings of a cello or violine will be more audible, more fluent, more realistic, finer details. ...technically you lower EMF, make life easier for the first choke, help the transistion between the two rectifiers etc.
I build in switches in my psu, you can switch back and fore to observe this effect without the need to switch off the amp...and as this cap should be of a size where you actually do not change HV, you dont listen to a changed bias...but the effect of this cap. Please use highest quality here...no oilers. I use Miflex KPCU1 here or Duelund cast (driver sction at 350V). At the 950V supply I use Mundorf Silver/gold/oil.
Are those chokes of Monolith two coil designs ? So do you have a choice to pit them in series or parallel those coils ? In that case you could try to parallel the two windings of the second choke, lower the resistance by a factor of four and see what happens.
I build in switches in my psu, you can switch back and fore to observe this effect without the need to switch off the amp...and as this cap should be of a size where you actually do not change HV, you dont listen to a changed bias...but the effect of this cap. Please use highest quality here...no oilers. I use Miflex KPCU1 here or Duelund cast (driver sction at 350V). At the 950V supply I use Mundorf Silver/gold/oil.
Are those chokes of Monolith two coil designs ? So do you have a choice to pit them in series or parallel those coils ? In that case you could try to parallel the two windings of the second choke, lower the resistance by a factor of four and see what happens.
Last edited:
Update, the cathode bypass cap for the 45B is now connected directly to B+ prior to the output transformer. As you probably know this is called the ultra path. Also I connected the four ohm tab on the output transformer. I did both of these changes at the same time so I’m not sure which of theChanges is making the difference. But there is a much cleaner mid range and upper frequency with the violin and piano. This is clearly audible the tone is more sweet and well-defined and has the leading edge attack that I’m looking for. Also note I ordered the new 947d caps as recommended.
May I offer some tube porn for you amusement?
These are the candidates we talked about...
IMG-20210814-200048 — ImgBB
These are the candidates we talked about...
IMG-20210814-200048 — ImgBB
SX11 has 308R DCR == too much turns.
With higher current the core would be over exciting.
If the manufacturer use higher gap (decreasing exciting), the inductance would be lesser than optimal for 5k transformer.
CDE 947D - Blitz told me these are very fast sounding caps. For his line arrays he needs as minimum a strong 10 Watt 300B - better with stronger transmitting tubes. He is using 300µF as C2 psu cap.
banpuku - your loudspeakers are power hungry - 130µF C2 for your psu is too small. Ask Blitz for values he has the experience with this cap.
My prior advice with small caps for your psu was wrong. My experience comes from the 98db/15 Ohm Goodmans Axiom louspeakers. They are a very easy load. My cap values will not work on your loudspeakers.
Good to hear that your sound is in progress.
Blitz - that are real toys for men. Wow you have the Molybdenum Elrog 845. Are they much better than graphite plates ?
banpuku - your loudspeakers are power hungry - 130µF C2 for your psu is too small. Ask Blitz for values he has the experience with this cap.
My prior advice with small caps for your psu was wrong. My experience comes from the 98db/15 Ohm Goodmans Axiom louspeakers. They are a very easy load. My cap values will not work on your loudspeakers.
Good to hear that your sound is in progress.
Blitz - that are real toys for men. Wow you have the Molybdenum Elrog 845. Are they much better than graphite plates ?
euro21 - spec: S-9 gapped for 80mA - 3.3K - dcr=106 - 33 Hy, S-11 gapped for 80ma - 5K - dcr=338 - 37Hy
They have the same core size, - same airgap ?
I am confused: S-11 much higher dcr than S-9 and inductance is not much higher. For me - higher dcr means more windings, wich should result in much higher inductance than 37 Hy.
I don't understand it.
They have the same core size, - same airgap ?
I am confused: S-11 much higher dcr than S-9 and inductance is not much higher. For me - higher dcr means more windings, wich should result in much higher inductance than 37 Hy.
I don't understand it.