Wow! @Never Get Old, thanks so much for the thorough response! I did watch the XrayTonyB videos yesterday and that was definitely helpful, but having you as a willing resource assuming I find myself in need of any input definitely makes me feel far more confident! Leaning towards pulling the trigger - I'll keep you posted. Thanks again!
Start a build thread with some photos if you do it. That helps others in the future, and it gives you a place to get advice if needed.
Let me know if you need the directions. The Google drive with them should still be working.
You can get coupons and codes for discounts on AliExpress if you watch and wait. I combined two different discounts on my second kit and paid only $312.81 with shipping and tax included. Be careful which seller you use. I used "Helen Electronic Audio Store" with no problems.
https://www.aliexpress.us/item/3256802532801472.html
Let me know if you need the directions. The Google drive with them should still be working.
You can get coupons and codes for discounts on AliExpress if you watch and wait. I combined two different discounts on my second kit and paid only $312.81 with shipping and tax included. Be careful which seller you use. I used "Helen Electronic Audio Store" with no problems.
https://www.aliexpress.us/item/3256802532801472.html
More specifically:
- Will EL84 work? - Yes. EL84 can be used in place of 6P14, 6P14P, 6P14P-EV, and 6P14P-ER in this amplifier.
- Sound quality will depend on the quality of the EL84 used of course. Sovtek EL84M actually is a 6P14P-EV made in the same Reflektor plant in Russia, so I am told. They have a reputation online for durability.
- Tube life of EL84 relative to others:
- If you use 120 volt power with the 200 ohm resistor in the power supply as I indicated, and 160 ohm bias resistors instead of the 150 resistors included in the kit, voltage should be about 335 volts and plate dissipation should be somewhere around 10 watts. The dissipation limit for the EL84 is 12 watts, so that is within spec.
- In comparison, the dissipation limit for all of the Russian 6P14P tube variants is 14 watts, so there is more margin there with the Russian tubes.
- The Chinese EL84 or 6P14 is rated 12 watts, but they have a bad reputation for quality control and total intolerance of any screen voltage over 300. I was glad to see PSvane EL84 in the kit that I just received. I hope they are genuine as PSvane is said to make decent tubes.
- All of these tubes are running at about 25 volts over max specification, but I don't consider it a problem as the screen voltage is regulated at around 297 volts and reports online, and noted in the user manual, indicate that keeping that screen voltage below 300 and keeping dissipation at less than maximum is sufficient for satisfactory tube life. The optional 91V Zener diode is used when needed to get that voltage below 300 and keep it there.
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@tbaashus Ik kan de montagehandleiding niet downloaden, waarschijnlijk omdat ik nog onder moderatie sta. Kun je de handleiding naar mijn emailadres sturen svp? rpmccloud1957@ziggo.nl Bedankt Mccloud
I can't download the assembly manual, probably because I'm still under Moderation. Can you please send the manual to my email address? rpmccloud1957@ziggo.nl
Thanks Mccloud
Thanks Mccloud
I think I by accident have deleted the file with the English translation, but the link to the Chinese original still seems to work.
https://drive.google.com/file/d/1S_Yz822MBgqkhp78-bDIAKwqcYnHMlps/view?usp=sharing
The file is too big to send as attachment.
Oops. That's not good. I still have it. @tbaashus Can you give me a link so I can upload it again?
@Mccloud Post in het Engels alstublieft https://translate.google.com/
@Mccloud - email sent, but your email address is rejecting it because the file is too large.
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@ never get old.
I would like to build the kit and could use the assembly instructions. Do you have the link for me with the assembly instructions in English? Thank you in avances.
Mccloud
I would like to build the kit and could use the assembly instructions. Do you have the link for me with the assembly instructions in English? Thank you in avances.
Mccloud
@Mccloud I have uploaded the directions, translated to English, to a Google drive. Try this link:
https://drive.google.com/file/d/1e6C1yM-10nynSAAbiULZAbfQxw6WqdfS/view?usp=drive_link
Let me know if it works please.
Merry Christmas everyone!
https://drive.google.com/file/d/1e6C1yM-10nynSAAbiULZAbfQxw6WqdfS/view?usp=drive_link
Let me know if it works please.
Merry Christmas everyone!
Mccloud,
If you are new to DIY one of the best things you can get is a digital multimeter. It doesn't have to be an expensive one, 20 to 30 Euros should be fine. Measure every resistor before you assemble it to the board.
Most projects are compromised by hurried assembly and poor soldering. Take your time. To make soldering easier, wipe the board and all component leads with isopropyl or methyl alcohol before beginning assembly. Where possible, especially tube sockets, solder on both side of the board.
Good Luck!
If you are new to DIY one of the best things you can get is a digital multimeter. It doesn't have to be an expensive one, 20 to 30 Euros should be fine. Measure every resistor before you assemble it to the board.
Most projects are compromised by hurried assembly and poor soldering. Take your time. To make soldering easier, wipe the board and all component leads with isopropyl or methyl alcohol before beginning assembly. Where possible, especially tube sockets, solder on both side of the board.
Good Luck!
Per page 10 of the direction manual:
Before starting work, test the components one by one.
If there is any problem with the values, especially for resistors, check the color bands. It is
likely that the seller did not send the wrong parts. Use a multimeter to test all of the
resistances to avoid big trouble later.
Although not required, I also matched the resistors and caps in pairs per channel and matched left-right where appropriate. It can't hurt and only takes a few minutes.
You would be surprised. I have read threads in the past where people, 1) Didn't test and instead trusted what was written on the paper tabs or bags with the resistors and caps, and 2) Didn't match because 1% or 5% is "close enough" and won't make any difference. My approach is that maybe matching isn't necessary, but it also is free, so why not do it as long as we are testing every one of them anyway.
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Hello all,
I am purchasing one of these kits second hand and already assembled. I am in the US and have voltage in the house at 120.2+.
I have not gone through all 14 page of this post but have read enough to see that tube longevity is compromised running this high voltage without changing out a resistor(?) to compensate. I am not much for the science behind this but know enough to be dangerous. So in laymen terms, The system is designed for 110v so a 120v source makes the power tubes run hotter than designed which makes them fail prematurely. and... even though the manufactures says EL84s sound better than the 614P, they are designed to run a lower current still yet and fail considerably quicker.
So what specifically should I be looking at when I get the amp to see if its got the stock configuration? or been modified to run better at 120v?
My second question relates to the loudness circuit and age of this particular amp. I read enough to know that Tony bypassed the loudness. Why?
I have a pair of highly efficient Coral speakers that are 16ohm by design. They lack a bit in the bass frequencies so I am hopeful this loudness circuit improves the bass response a bit. What drew me to the amp was the fact that on the back of the amp it has a selector for 8 ohm as well 16 ohms tap.
Since the speakers previous owners wired in a 16 ohm horn, I am looking to see what I prefer better, the 8 ohm 2 driver configuration, or the 16 ohm single Coral driver design.
Thanks for reading and responding.
Joe
I am purchasing one of these kits second hand and already assembled. I am in the US and have voltage in the house at 120.2+.
I have not gone through all 14 page of this post but have read enough to see that tube longevity is compromised running this high voltage without changing out a resistor(?) to compensate. I am not much for the science behind this but know enough to be dangerous. So in laymen terms, The system is designed for 110v so a 120v source makes the power tubes run hotter than designed which makes them fail prematurely. and... even though the manufactures says EL84s sound better than the 614P, they are designed to run a lower current still yet and fail considerably quicker.
So what specifically should I be looking at when I get the amp to see if its got the stock configuration? or been modified to run better at 120v?
My second question relates to the loudness circuit and age of this particular amp. I read enough to know that Tony bypassed the loudness. Why?
I have a pair of highly efficient Coral speakers that are 16ohm by design. They lack a bit in the bass frequencies so I am hopeful this loudness circuit improves the bass response a bit. What drew me to the amp was the fact that on the back of the amp it has a selector for 8 ohm as well 16 ohms tap.
Since the speakers previous owners wired in a 16 ohm horn, I am looking to see what I prefer better, the 8 ohm 2 driver configuration, or the 16 ohm single Coral driver design.
Thanks for reading and responding.
Joe
I wouldn't be too concerned about impedance selection. A 16 ohm speaker should work OK on the 8 ohm tap on the amp. Speaker impedances vary with frequency and often drop to less than their nominal value.
The loudness control can be verry heavy-handed, often giving too much bass boost. Some music streamers have digital tone controls that offer fine adjustments. I know Bluesound Nodes offer this.
IIRC, these amps regulate the screen voltage to a little less than 300 volts, so no need worry there. If you are worried about high line voltage, the effect that might be most concerning is filament over-voltage. The nominal is 6.3 but as high as 6.5 should be OK. Higher than that, consider putting resistors in series where the filament taps connect to the board. Put one resistor on each lead. I've used 0.1 ohm, 3W from Mouser, p/n 279-ROX3SJR10. Buy at least four. You might need to double-up, parallel two on each "side" for 0.05 ohms.
Goo luck,
S.
The loudness control can be verry heavy-handed, often giving too much bass boost. Some music streamers have digital tone controls that offer fine adjustments. I know Bluesound Nodes offer this.
IIRC, these amps regulate the screen voltage to a little less than 300 volts, so no need worry there. If you are worried about high line voltage, the effect that might be most concerning is filament over-voltage. The nominal is 6.3 but as high as 6.5 should be OK. Higher than that, consider putting resistors in series where the filament taps connect to the board. Put one resistor on each lead. I've used 0.1 ohm, 3W from Mouser, p/n 279-ROX3SJR10. Buy at least four. You might need to double-up, parallel two on each "side" for 0.05 ohms.
Goo luck,
S.