Please Help for my Seduction problem.
- Thread starter jamestw
- Start date
Paul Joppa said:
I can only find a 0.5 ohm 2W resistor from local, its value within in suggested range but I'm not sure 2W is OK ?
After put it parelled with 1.2 ohm resistor (T6 - T9), that did work.
Now I got the heater reading both 6.1 vdc on A5, B5. (before they were only 5.2 vdc).
but the other readings on tube sockets are lower than before, especially the plate voltages A1,B1 and A6,B6 .the B1, B6 just lower than -15% tolerance of 70vdc ... Is there something wrong ?
Voltage checks :
(Terminal/Voltage)...(vdc reading Before add parelle resistor)...(vdc reading After add parelle resistor)
(T6/6.5 vdc)...(6.0)...(6.48)
(T9/6.0 vdc)...(5.3)...(6.1)
(T12/135 vdc)...(115.5)...(116.3)
(T15/148 vdc)...(132.4)...(132.8)
(T25/160 vdc)...(149.8)...(150)
(T27,T37 / 70 vdc)...(68.2 , 64.7)...(62.8 , 59.5)
(T29,T39 / 70 vdc)...(64 , 60.6)...(58.8 , 55.8)
(T30,T40 / 70 vdc)...(63.4 , 60)...(58.4 , 55.3)
(T34,T44 / 135 vdc)...(114.6 , 114.4)...(116 , 115.8)
(A1,B1 / 70 vdc)...(67.4 , 64)...(62.3, 58.7)
(A3,B3 / 1.6 vdc)...(1.5 , 1.5)...(1.5 , 1.5)
(A5,B5 / 6.0 vdc)...(5.2, 5.2)...(6.1 , 6.1)
(A6,B6 / 70 vdc)...(67.5 , 63.9)...(62.5 , 59)
(A8,B8 / 1.6 vdc)...(1.5 , 1.5)...(1.5 , 1.5)
james
Paul Joppa
Moderator
Excellent!
2 watts is better than 1 watt, so that value is just fine - I should have said "1 watt or greater". The voltage of 6.1v is very good - my design intention was to run the tubes at 6.0, with an acceptable range of 5.7 to 6.3v.
The tubes are able to conduct more current when the cathode is properly heated, which pulls the plate voltage down a bit - that's why those voltages have dropped. It is actually a good sign, and it's not uncommon for the plate voltages to drop to 55-60 volts. It's not a problem.
2 watts is better than 1 watt, so that value is just fine - I should have said "1 watt or greater". The voltage of 6.1v is very good - my design intention was to run the tubes at 6.0, with an acceptable range of 5.7 to 6.3v.
The tubes are able to conduct more current when the cathode is properly heated, which pulls the plate voltage down a bit - that's why those voltages have dropped. It is actually a good sign, and it's not uncommon for the plate voltages to drop to 55-60 volts. It's not a problem.
Grainger49
New member
James,
Are you up and running yet?
Are you up and running yet?
Hi Grainger,
I just back from the long Chinese Lunar New Year holiday, I was out of town last week can not get access to internet easy ...
I have ran the Seduction with my TT (Micro Seiki DQX1000) and Yamaha RX-V661 receiver which is an integrated amp has its build-in MM input which is not a bad build-in MM stage, so I have compared RX-V661 stock MM stage with Seduction... And I have a confidence to say the Seduction is totally superior than RX-V661 build-in MM stage, in everywhere.
Till now, my Seduction only ran about 15 hours, but I can tell it did has difference sounding everyday when I played records - in good way.
It's hard to me to explain how its difference each time I listened records with Seduction, It had a R&L channel balance issue that I reported last week, but now both channels have balanced sound as 6922EH tubes and all the parts of Seduction has break-in 10 more hours.
Now I just put Seduction on rack at convenience, I'll settle down it at a proper position on the rack in next few days, and will post some photos here.
I got a serious hum problem at first two days after connected the Seduction to Micro and Yamaha system, not surprised to me, which I has expected, and I tried/played the grounding in many ways from tonearms (two tonearms on Micro TT), TT, SUT, to Seduction, then to Yamaha amp... Finally I have an extra jump wire connect from ground post of Seduction to the metal frame of rack, it does work, it calm down the hum very well
I know the hum is still there when I crank Yamaha volume up to 0db the hum and noise from speakers loudly I can hear, But, it does not bother me now, because at my normal listening level (Yamaha's volume at -30db~-40db) I can not hear any hum or noise, even put my ears close next to speaker drivers, I can only hear a dead quiet
BTW, the volume control range of my Yamaha RX-V661 amp is from -80db to +15db and it drive a pair of very sensitive JBL 3622N horn speakers --- 101db, 4ohm --- I guess this also is a factor that I can still hear hum and noise from speaker when the volume crank to 0db.
Besides, I think my Seduction has not be completed well yet, as I left full length of leads of M-cap SIO cap soldered to connections of Section, I was thinking that I might change to other caps later... But now, I think I will cut the M-cap leads as short as possible and resolder them again, in this way might can reduce hum and noise further more.
I'm happy with my Seduction, now with my first 10 more hours listening it does sound much more clear and show me every details from my records - if compare to my Yamaha build-in MM stage.
The bass is more tight, clear and with textures in there - this is very important to me. (and please note, Yamaha's 'Natural Sound' tech make the bass sounded well already, this amp is not a cheap shit, to compare with my other system, Mcintosh C100 pre + MC352 amp that I can not tell which one sounded better than the other, I love them both.) - But the Seduction make the bass a lot better I've heard.
Since I did not use the stock caps in Seduction, two 0.1uf in interstages and two 0.47uf in outputs, I put M-cap SIO in there directly. I can not tell if the M-caps make Seduction sounds so smoothly or improved more smooth sounding ? I can only say the sound is soooooo smooth, plus, a deeper dimension - Compare to the Yamaha build-in MM stage of course.
I did build my Seduction followed the steps from Wonderful World of Audio website, and of course the excellent building guide from kit, thanks to you guys --- I have a lot of fun with this stuff.
james
I just back from the long Chinese Lunar New Year holiday, I was out of town last week can not get access to internet easy ...
I have ran the Seduction with my TT (Micro Seiki DQX1000) and Yamaha RX-V661 receiver which is an integrated amp has its build-in MM input which is not a bad build-in MM stage, so I have compared RX-V661 stock MM stage with Seduction... And I have a confidence to say the Seduction is totally superior than RX-V661 build-in MM stage, in everywhere.
Till now, my Seduction only ran about 15 hours, but I can tell it did has difference sounding everyday when I played records - in good way.
It's hard to me to explain how its difference each time I listened records with Seduction, It had a R&L channel balance issue that I reported last week, but now both channels have balanced sound as 6922EH tubes and all the parts of Seduction has break-in 10 more hours.
Now I just put Seduction on rack at convenience, I'll settle down it at a proper position on the rack in next few days, and will post some photos here.
I got a serious hum problem at first two days after connected the Seduction to Micro and Yamaha system, not surprised to me, which I has expected, and I tried/played the grounding in many ways from tonearms (two tonearms on Micro TT), TT, SUT, to Seduction, then to Yamaha amp... Finally I have an extra jump wire connect from ground post of Seduction to the metal frame of rack, it does work, it calm down the hum very well
I know the hum is still there when I crank Yamaha volume up to 0db the hum and noise from speakers loudly I can hear, But, it does not bother me now, because at my normal listening level (Yamaha's volume at -30db~-40db) I can not hear any hum or noise, even put my ears close next to speaker drivers, I can only hear a dead quiet
BTW, the volume control range of my Yamaha RX-V661 amp is from -80db to +15db and it drive a pair of very sensitive JBL 3622N horn speakers --- 101db, 4ohm --- I guess this also is a factor that I can still hear hum and noise from speaker when the volume crank to 0db.
Besides, I think my Seduction has not be completed well yet, as I left full length of leads of M-cap SIO cap soldered to connections of Section, I was thinking that I might change to other caps later... But now, I think I will cut the M-cap leads as short as possible and resolder them again, in this way might can reduce hum and noise further more.
I'm happy with my Seduction, now with my first 10 more hours listening it does sound much more clear and show me every details from my records - if compare to my Yamaha build-in MM stage.
The bass is more tight, clear and with textures in there - this is very important to me. (and please note, Yamaha's 'Natural Sound' tech make the bass sounded well already, this amp is not a cheap shit, to compare with my other system, Mcintosh C100 pre + MC352 amp that I can not tell which one sounded better than the other, I love them both.) - But the Seduction make the bass a lot better I've heard.
Since I did not use the stock caps in Seduction, two 0.1uf in interstages and two 0.47uf in outputs, I put M-cap SIO in there directly. I can not tell if the M-caps make Seduction sounds so smoothly or improved more smooth sounding ? I can only say the sound is soooooo smooth, plus, a deeper dimension - Compare to the Yamaha build-in MM stage of course.
I did build my Seduction followed the steps from Wonderful World of Audio website, and of course the excellent building guide from kit, thanks to you guys --- I have a lot of fun with this stuff.
james
Hi Paul,
Since you guided me to add a parallel resistor on heater power supply brought up voltage to 6.1vdc. I'm wondering if I could do the same way to add a parallel resistor to high voltage power supply (T15/T12 , or T25/T15 , or somewhere ?) to increase the C4S voltage and two plates voltage ?
I know you've mentioned several times, the lower plate voltage is not a problem. But, does the higher plate voltage can offer more gain (or μ) ?
If so, the higher plate voltage will increase noise or other disadvantages ?
... sorry, if this is a stupid question , I'm in learning these tube's knowledges.
Thanks,
james
Since you guided me to add a parallel resistor on heater power supply brought up voltage to 6.1vdc. I'm wondering if I could do the same way to add a parallel resistor to high voltage power supply (T15/T12 , or T25/T15 , or somewhere ?) to increase the C4S voltage and two plates voltage ?
I know you've mentioned several times, the lower plate voltage is not a problem. But, does the higher plate voltage can offer more gain (or μ) ?
If so, the higher plate voltage will increase noise or other disadvantages ?
... sorry, if this is a stupid question
, I'm in learning these tube's knowledges.Thanks,
james
Grainger49
New member
James,
Dispersed comments below. Man, sounds like you are almost there.
I
Dispersed comments below. Man, sounds like you are almost there.
jamestw said:
I
Paul Joppa
Moderator
You have the C4S, which isolates each triode from the power supply. As long as the power supply voltage is at least 10 volts greater than the plate voltages, raising the supply voltage will have no effect at all.jamestw said:
If you had used the resistor loads, you would want to get the voltage up. But changing the resistors in the power supply would provide less hum filtering, which would not be a satisfactory solution. You'd have to replace at least on of the resistors with a filter choke; in that case you'd also have to find a suitable location and orientation for the choke to prevent it from picking up magnetic-field hum. It's easier, less expensive, and sounds better to use the C4S loads.
jamestw said:
That will be good, I'm interesting to know what tweaks I can do on Seduction.
jamestw said:
Oh, the rack does not ground itself. It just a common 'L' shape rack that can easy buy from hardware stores, each L shape frame has many punched holes so you can adjust each level's height as you want, add more beams and you get more levels. These frames-beams made by steel with paint coating. This kind of rack has a strong construction once it be assembled, normally it can take 300 kgs or more without any problem.
jamestw said:
