AudioCircle
Audio/Video Gear and Systems => Tube-o-phile Circle => Topic started by: Limberpine on 28 Dec 2020, 09:41 pm
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I have been considering these and wanted to see what other thoughts and experiences have been with them? I've heard there can be some hum issues, so I was considering going with an outboard power supply to help with any potential hum, but will also be running them on La Scalas, so given their sensitivity, I wanted to see if anybody else has run the 2 together or a speaker of similar sensitivity to se what their experience was like?
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Welcome
I will move this topic to the Tubeophile Circle as You already started a topic in the Starting Block.
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Welcome!
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I don't have the monoblocks, but I use an Eaton 45 frequently with my Spatial X5s (97db). I love the amp, it's one of my favorites. The hum was noticeable until I upgraded the tubes, which significantly reduced the hum and the noise floor. I put in a pair of Emission Labs 45 mesh plate, and I rolled the 6SN7s a few times. At the moment I'm using a pair of Shaguang Black Treasure CV181-Z. The EML tubes transformed the amp.
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Some sino amps use a pot tô lower the hum, Its a second class solution but solve the prob.
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I don't have the monoblocks, but I use an Eaton 45 frequently with my Spatial X5s (97db). I love the amp, it's one of my favorites. The hum was noticeable until I upgraded the tubes, which significantly reduced the hum and the noise floor. I put in a pair of Emission Labs 45 mesh plate, and I rolled the 6SN7s a few times. At the moment I'm using a pair of Shaguang Black Treasure CV181-Z. The EML tubes transformed the amp.
Great to know! Do you think going with the outboard power supply would be a measurable help with these amps?
And when you said you rolled the 6SN7s, you did that in an effort to find low noise tubes? Is that why you did it?
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Some sino amps use a pot tô lower the hum, Its a second class solution but solve the prob.
Sino amps?
What woudl be the first class solution?
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Sino amps?
What woudl be the first class solution?
Chinese amps.
What woudl be the first class solution?
Its a better circuit assemblage, construction etc
The amp table must be alu or copper, not steel which is magnetic, one of the techniques to reduce background noise that builders use is to bring the circuit closer to the alu table so that it absorbs the parasitic static voltages that circulate inside the amp during use, certainly there are other means of reducing noise.
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Chinese amps.
What woudl be the first class solution?
Its a better circuit assemblage, construction etc
The amp table must be alu or copper, not steel which is magnetic, one of the techniques to reduce background noise that builders use is to bring the circuit closer to the alu table so that it absorbs the parasitic static voltages that circulate inside the amp during use, certainly there are other means of reducing noise.
I see. The Alan Eatons are made here in the US though.
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Great to know! Do you think going with the outboard power supply would be a measurable help with these amps?
And when you said you rolled the 6SN7s, you did that in an effort to find low noise tubes? Is that why you did it?
The new EML 45s mitigated most of the noise. Not sure on the power supply. Alan had a 2a3 amp with external PS on eBay recently, he claimed it eliminated the noise. But there's other things to consider. I'll PM you my thoughts.
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The new EML 45s mitigated most of the noise. Not sure on the power supply. Alan had a 2a3 amp with external PS on eBay recently, he claimed it eliminated the noise. But there's other things to consider. I'll PM you my thoughts.
Thanks! :thumb:
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I have an Alan Eaton 45 amp (not monoblocks) and it's paired with Tekton Lore speakers (98 db, but honestly probably 96db). It has a very very small hum with your ear to the speaker, but from 3 feet I cant hear a thing. I have NOS globe 45s in there (RCA) and RCA 5682 (6SN7) black plates. You can read about his process and parts (mainly upcycled parts) on ebay from his former posts, or the glowinthedark website.
I'll say that it sounds absolutely great for the price. I had a Decware SE84UFO before it.
I'm the kind of guy who won't 'go cheap' but I can't help but to try and find the BEST value, and for a handmade amp here in America, with the Tamura output transformer - I think this is it! It sounds beautiful in all the ways you've read a 45 should. Maybe there's a much better 45 amp out there, but I can't imagine anything as good of a value.
The downside - I'm likely going to sell mine as I do find that although it gets loud, it has its limitations at about 1.5 watts per channel. There's just no way with my speakers to really get hit in the chest. I 100% knew this coming in, especially after having the Decware Zen driving my Lores for a few years at 2.3 watts. But I just needed to see what Alan's 45 was all about, and it delivers.
I'm likely next going to have Alan build me 300b monoblocks to go from 1.5 watts to about 5 watts per channel. I just hope it still sounds as sweet, but I do think Alan is gifted and he could charge more than he does. I'm glad he doesn't though.
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My AE 45 requires your ear to be next to the driver (97-98 db single drivers) to hear anything. Very much like my old Decware UFO. It is a glorious single ended triode, w the right speakers.
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I have an Alan Eaton 45 amp (not monoblocks) and it's paired with Tekton Lore speakers (98 db, but honestly probably 96db). It has a very very small hum with your ear to the speaker, but from 3 feet I cant hear a thing. I have NOS globe 45s in there (RCA) and RCA 5682 (6SN7) black plates. You can read about his process and parts (mainly upcycled parts) on ebay from his former posts, or the glowinthedark website.
I'll say that it sounds absolutely great for the price. I had a Decware SE84UFO before it.
I'm the kind of guy who won't 'go cheap' but I can't help but to try and find the BEST value, and for a handmade amp here in America, with the Tamura output transformer - I think this is it! It sounds beautiful in all the ways you've read a 45 should. Maybe there's a much better 45 amp out there, but I can't imagine anything as good of a value.
The downside - I'm likely going to sell mine as I do find that although it gets loud, it has its limitations at about 1.5 watts per channel. There's just no way with my speakers to really get hit in the chest. I 100% knew this coming in, especially after having the Decware Zen driving my Lores for a few years at 2.3 watts. But I just needed to see what Alan's 45 was all about, and it delivers.
I'm likely next going to have Alan build me 300b monoblocks to go from 1.5 watts to about 5 watts per channel. I just hope it still sounds as sweet, but I do think Alan is gifted and he could charge more than he does. I'm glad he doesn't though.
96db should cut it however obviously not. I heard a slight hum with 100db speakers. Adjusted hum pot, gone. When I use the 18W mono blocks more dynamics but less harmonic structure. I use a preamp with gain controls bypassed. More dynamic with pre in. Did not like using pre with gain controls at unity gain compared to bypassing them. The coulping caps can be improved as well. Cuts down ANY noise. Alan makes a wonderful 300B amp or mono blocks.
charles
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All great information! Thank you all for sharing your experiences! With the 45's you have purchased from Alan, do any of you believe it would be worth the extra money to have him build the 45 with an outboard power supply?
Another member here, sent me some videos of his AE 45 playing and the noise that is heard is slight, which was great to hear!
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perhaps but....you might be better served with NOS tubes, coupling caps, line level wire, and potentiometers. it certainly upped the ante on an already great sounding amp! mine is silly quiet for being DH. although I would not mention any mods to Alan :nono:
(https://www.audiocircle.com/image.php?id=219145)
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All great information! Thank you all for sharing your experiences! With the 45's you have purchased from Alan, do any of you believe it would be worth the extra money to have him build the 45 with an outboard power supply?
Another member here, sent me some videos of his AE 45 playing and the noise that is heard is slight, which was great to hear!
Maybe a slight improvement in sound stage. Changing the coupling caps will yield more. The gain controls can be improved. I bypassed mine using an active preamp instead. HUGE improvement.
charles
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Maybe a slight improvement in sound stage. Changing the coupling caps will yield more. The gain controls can be improved. I bypassed mine using an active preamp instead. HUGE improvement.
charles
Charles, how did you bypass the gain pots? Did you add in a resistor to ground? I've been thinking about doing this, I'm not a huge fan of the dual gain controls.
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Just connected input to to gain control into board where output of gain control goes. Jan has found changing the wire to silver was an improvement as well.
charles
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perhaps but....you might be better served with NOS tubes, coupling caps, line level wire, and potentiometers. it certainly upped the ante on an already great sounding amp! mine is silly quiet for being DH. although I would not mention any mods to Alan :nono:
(https://www.audiocircle.com/image.php?id=219145)
Oh, mum would be the word there! I have some basic soldering skills, would that suffice? Or would you be willing to help advise me should I chose to do that?
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I would suggest a inductor instead coupling caps, and two power transformers - heating and HV instead out board supply, If funds allow.
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Oh, mum would be the word there! I have some basic soldering skills, would that suffice? Or would you be willing to help advise me should I chose to do that?
I would think so. Maybe some youtube vids and a few practice rounds. Mods certainly aren't necessary with the AE SET but it does lower the noise floor and let you hear further into the music. The TDK volume pots are much smoother, more usable range, and transparent than the alpha brand Alan supplies. Use some quality solder.
https://www.amazon.com/Cardas-Soldering-Eutectic-Silver-Solder/dp/B082J6SH4J/ref=sr_1_2_sspa?crid=CY3HPK7RUHGJ&dchild=1&keywords=cardas+solder&qid=1609935182&sprefix=cardas+%2Caps%2C195&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExWUtFOVFKMzM1MVJBJmVuY3J5cHRlZElkPUEwMjcyMzgxMU1EUUc2NzUwTUhUNyZlbmNyeXB0ZWRBZElkPUEwOTIyNTI5MUpWSURQWDMyMDQyViZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
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I would think so. Maybe some youtube vids and a few practice rounds. Mods certainly aren't necessary with the AE SET but it does lower the noise floor and let you hear further into the music. The TDK volume pots are much smoother, more usable range, and transparent than the alpha brand Alan supplies. Use some quality solder.
https://www.amazon.com/Cardas-Soldering-Eutectic-Silver-Solder/dp/B082J6SH4J/ref=sr_1_2_sspa?crid=CY3HPK7RUHGJ&dchild=1&keywords=cardas+solder&qid=1609935182&sprefix=cardas+%2Caps%2C195&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExWUtFOVFKMzM1MVJBJmVuY3J5cHRlZElkPUEwMjcyMzgxMU1EUUc2NzUwTUhUNyZlbmNyeXB0ZWRBZElkPUEwOTIyNTI5MUpWSURQWDMyMDQyViZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
Very good. Yeah, I def will listen to it first to see if its needed, but just wnated to get a handle on others impressions and then weigh, if I should pay the extra dough for the OPS when ready to order from Alan.
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makes complete sense. i didn't touch mine for five months while i got a feel.
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Just to reiterate - at 2.5 feet away from my speaker it’s dead quiet. That noise you heard about may not be the norm. It’s not for me. If my amp were quieter than it is - it wouldn’t matter as I couldn’t hear it.
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Just to reiterate - at 2.5 feet away from my speaker it’s dead quiet. That noise you heard about may not be the norm. It’s not for me. If my amp were quieter than it is - it wouldn’t matter as I couldn’t hear it.
Thanks!
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I have been considering these and wanted to see what other thoughts and experiences have been with them? I've heard there can be some hum issues, so I was considering going with an outboard power supply to help with any potential hum, but will also be running them on La Scalas, so given their sensitivity, I wanted to see if anybody else has run the 2 together or a speaker of similar sensitivity to se what their experience was like?
I've come to view outboard supplies in power amps as a compromise and expense that can be avoided with good design and layout. With any amplifier running AC filaments on DHT tubes, there will be some audible hum. With my 2A3 amp, with AC filaments, driving circa 99dB speakers that are easily "flat" to 50Hz (our line frequency), I can hear hum roughly 45cm (probably less) from the speakers, but no further away. If that level of noise is too great, I suggest using a separate, good quality filament transformer and well-designed DC filament supplies.
Chinese amps.
What woudl be the first class solution?
Its a better circuit assemblage, construction etc
The amp table must be alu or copper, not steel which is magnetic, one of the techniques to reduce background noise that builders use is to bring the circuit closer to the alu table so that it absorbs the parasitic static voltages that circulate inside the amp during use, certainly there are other means of reducing noise.
I agree with a need for better design and construction, though not the method suggested here. The closer components are to conductive metal, the greater the measurable parasitic capacitance. Considering that signal circuitry, in a power amplifier with any touchable conductive part, should be connected to earth, would “static” voltages be present? As for chassis materials, there is no universal agreement on what is best; it probably depends on what the designer is trying to achieve.
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If condutive metal table is a prob could de used acrylic 8mm as Joule Electra amps, the rec of alu is by Morgan Jones page 153 if I remember well, alu is not prefered by builders due higher price but its a very interesting opinion from MJ.
EDIT:
According Morgan Jones author in Building Valve Amplifiers/2004 page 85:
Steel is not suitable for the chassis of valve amplifiers. Steel is magnetic, and allows leakage flux from transformers to flowthrough the chassis and induce currents into the pins of the valves. If a steel chassis is unavoidable, induction into the chassis can be greatly reduced by fitting a non-ferrous gasket between transformers and the chassis; 1.5 mm Paxolin is ideal
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If condutive metal table is a prob could de used acrylic 8mm as Joule Electra amps, the rec of alu is by Morgan Jones page 153 if I remember well, alu is not prefered by builders due higher price but its a very interesting opinion from MJ.
EDIT:
According Morgan Jones author in Building Valve Amplifiers/2004 page 85:
Steel is not suitable for the chassis of valve amplifiers. Steel is magnetic, and allows leakage flux from transformers to flowthrough the chassis and induce currents into the pins of the valves. If a steel chassis is unavoidable, induction into the chassis can be greatly reduced by fitting a non-ferrous gasket between transformers and the chassis; 1.5 mm Paxolin is ideal
They are good points FRM. I think it depends on techniques, layout etc. How close does the socket need to be to the transformer and how small does the socket need to for currents to be induced into valve pins? What if you don't mount sockets to the chassis and chassis is not close to the valve pins? Plenty of highly-regarded commercial and DIY amps use magnetic chassis without issue - and I don't think it is always due to cost as Morgan suggests. Morgan's goals are minimising risks using simple build techniques in worst-case situations: conservative. I wonder what his thoughts regarding SET amps and full-range drivers would be?
If using a magnetic chassis, I prefer to mount all components, except transformers, on an industrial plastic sub-chassis, well away from the chassis. And I have been using non-magnetic stainless steel for chassis.
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They are good points FRM. I think it depends on techniques, layout etc. How close does the socket need to be to the transformer and how small does the socket need to for currents to be induced into valve pins?
Its not good a valve to be close the transformer for not overheat the transformer, rectification is a task that generates a lot of heat, rectifier tubes heat up more than others.
What if you don't mount sockets to the chassis and chassis is not close to the valve pins?
I do not have practical experience in distance of socket assemblies, but the distances present in audio amps are not a problem for the activation of the valve, the most careful builders keep the distances as short as possible for the effect of less loss in the musical signal.
Among the audio valves it was found that the 12AX7 has low power, I read on the site of a great builder that this tube cannot drive 1M of interconnect cable, however it suits very well to phono audio stage due the high gain of 100x.
Plenty of highly-regarded commercial and DIY amps use magnetic chassis without issue - and I don't think it is always due to cost as Morgan suggests. Morgan's goals are minimising risks using simple build techniques in worst-case situations: conservative.
Yes, they all use steel and are famous and expensive, its rare a brand use alu in tube amps, however STM Inspire amps use alu chassis made in house but a small one, changing a part will be difficult.
I wonder what his thoughts regarding SET amps and full-range drivers would be?
Iam glad to MJ for he expose this technical detail and others in his book, that has always been secretly hidden by the entire commercial audio world, they do not want the user to know what is good and what is bad so that their products are not exposed to the clinical eye of the audiophool that pays the money that these equips are priced.
If using a magnetic chassis, I prefer to mount all components, except transformers, on an industrial plastic sub-chassis, well away from the chassis. And I have been using non-magnetic stainless steel for chassis.
I think the chassis material can be easily used to model the amp sound.
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That is not where I was headed FRM... a lengthy discussion better had face-to-face, or over a beer. Let's not get caught up in that now and guide this back to something relevant to AE 45 amps.