Hello,
I am new in town! Think we all have a mutual hobby: DIY HiFi. A few other "hobbies" of mine:
- visiting Great Britain and our British friends,
- my lovely wife and our two grandchildren,
- riding with my BMW R1200rt motorbike.
Recently I bought an immaculate Yarland FV34CiiiSA for just € 65,- (50 Pounds). It sounds much better than my NAD C320bee, although the little Yarland lacks power to party! (It has only 12 Watts....) But it sounds GREAT!
This Yarland is already upgraded with Clarity Caps SA as coupling capacitors and a new and matched set of GE jan 5670 tubes. The four EL84 Shuguang power tubes are imho very good, but old ( 5 years?). I already tried matched JJ tubes, but the sound became harsh! So, no JJ's for me in this little amp.
But what tubes could I try to replace the old Shuguang tubes? TAD EL84STR? A bit more power, as they say. (made in China?) Sovtek? Russian and made by military specs.
Anyone who can give a good advice?
I am new in town! Think we all have a mutual hobby: DIY HiFi. A few other "hobbies" of mine:
- visiting Great Britain and our British friends,
- my lovely wife and our two grandchildren,
- riding with my BMW R1200rt motorbike.
Recently I bought an immaculate Yarland FV34CiiiSA for just € 65,- (50 Pounds). It sounds much better than my NAD C320bee, although the little Yarland lacks power to party! (It has only 12 Watts....) But it sounds GREAT!
This Yarland is already upgraded with Clarity Caps SA as coupling capacitors and a new and matched set of GE jan 5670 tubes. The four EL84 Shuguang power tubes are imho very good, but old ( 5 years?). I already tried matched JJ tubes, but the sound became harsh! So, no JJ's for me in this little amp.
But what tubes could I try to replace the old Shuguang tubes? TAD EL84STR? A bit more power, as they say. (made in China?) Sovtek? Russian and made by military specs.
Anyone who can give a good advice?
I have the same amp in the guest room though it hasn't seen much use over the last couple of years. Soviet NOS 6p14p-EV or ER would be a good choice for power tubes and can still be found on ebay with decent prices.
If you can find any EI (Yugoslavia, not the ones labeled 'Made in Serbia' on the box) - TAD used to sell them but they may have run out. I most enjoyed JAN 5670 + EI EL84s and 6N3P-EV + Telam EL84 combinations, keep in mind that my amp is triode-connected (3W/ch but more than enough for 96dB speakers).
P.S I still have the original Chinese military tubes that came with the amp and were only used for a few hours, you can have them for a few Euros each and the cost of postage (within Europe).
If you can find any EI (Yugoslavia, not the ones labeled 'Made in Serbia' on the box) - TAD used to sell them but they may have run out. I most enjoyed JAN 5670 + EI EL84s and 6N3P-EV + Telam EL84 combinations, keep in mind that my amp is triode-connected (3W/ch but more than enough for 96dB speakers).
P.S I still have the original Chinese military tubes that came with the amp and were only used for a few hours, you can have them for a few Euros each and the cost of postage (within Europe).
#1 Welcome. Looks like you have a great deal for around $75.
#2 In your amp, there should be two AC balance trim pots inside, one for each channel. I would put the JJ back in and use this trim pot to see if the sound improve first. Note: For inexperienced, going back may take time (or not easy) once you touched that. You can take an ohm meter and measure the previous value before you change anything. Also note which tube go to which location.
Here is a version of the schematic for your amp.
Attachments
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Thanks Alllensoncanon, but the Fv34ciii is fitted with an auto-bias. Already spoke with the retailer and his answer was to skip the JJ's. "JJ's are perfect tubes, however not with the FV34CIII", he said. His advice was to stick to the Shuguang EL84 tubes and go for the STR version of them...... Don't know where STR stands for....
But I am a bit hard headed and was wondering if other powertubes would give a bit more power.... The TAD EL84str could be that tube, however I have zero experience with the TAD- tubes.
Thanks for your advice.
But I am a bit hard headed and was wondering if other powertubes would give a bit more power.... The TAD EL84str could be that tube, however I have zero experience with the TAD- tubes.
Thanks for your advice.
Werner,
Simply "rolling" tubes will not increase power O/P. Re-engineering is necessary and the O/P transformers may already be at the limit of their capability. Leaving well enough alone strikes me as the prudent thing to do.
The "best" current production EL84 variant is New Sensor's "reissue" Gold Lion N709. However, best all around does not mean best in your amp. JJ's EL84 has a good reputation and they didn't do well. The "reissue" N709s carry a hefty price tag and could turn out to be a costly failure. I suggest you try the Russian 6Π14Π-EB (6p14p-ev), AKA EL84M. That variant is not especially costly, along with being very tough. If nothing else, the 6Π14Π-EB rates to exhibit a good service life.
Simply "rolling" tubes will not increase power O/P. Re-engineering is necessary and the O/P transformers may already be at the limit of their capability. Leaving well enough alone strikes me as the prudent thing to do.
The "best" current production EL84 variant is New Sensor's "reissue" Gold Lion N709. However, best all around does not mean best in your amp. JJ's EL84 has a good reputation and they didn't do well. The "reissue" N709s carry a hefty price tag and could turn out to be a costly failure. I suggest you try the Russian 6Π14Π-EB (6p14p-ev), AKA EL84M. That variant is not especially costly, along with being very tough. If nothing else, the 6Π14Π-EB rates to exhibit a good service life.
STR is a marketing name for Special Tube Request. Unless this difference is specified in a data sheet which in this case, it is not, it is just another name. The EL84 by itself won't give you more power. Changing the surround circuits will, assuming those STR-EL84 can really handle the extra power.
The trim pot in your amp is not for DC bias. It is used for AC balance (to balance non-matching EL84). It is possible that your two JJ EL84 (or the previous old EL84) are not exact match. Hence the tone difference. Unless you are doing the tube matching yourself, I wouldn't expect much. I would also make sure the circuit is tuned the way it should, before rolling any tubes.
The trim pot in your amp is not for DC bias. It is used for AC balance (to balance non-matching EL84). It is possible that your two JJ EL84 (or the previous old EL84) are not exact match. Hence the tone difference. Unless you are doing the tube matching yourself, I wouldn't expect much. I would also make sure the circuit is tuned the way it should, before rolling any tubes.
Analogadikt,
My speakers are home made. 2-way with a full-range Jordann.
Spl: 85dB which is pretty average.
The power of my Yarland is sufficient! A tight bass would be welcome. The Shuguang tubes give a smooth, almost elastic-sounding bass.
Other tubes might offer a firmer bass reproduction, like the TAD el84 str, as suggested by Tone Factory.
I will definitely keep you informed. My wife is already very pleased with the Yarland the way it sounds right now: wonderful mids and extremely airy hights. Together with an wide and stretched stage, this little amplifier is stunning the way it performs right now.
My speakers are home made. 2-way with a full-range Jordann.
Spl: 85dB which is pretty average.
The power of my Yarland is sufficient! A tight bass would be welcome. The Shuguang tubes give a smooth, almost elastic-sounding bass.
Other tubes might offer a firmer bass reproduction, like the TAD el84 str, as suggested by Tone Factory.
I will definitely keep you informed. My wife is already very pleased with the Yarland the way it sounds right now: wonderful mids and extremely airy hights. Together with an wide and stretched stage, this little amplifier is stunning the way it performs right now.
A tube amp lacks the gargantuan damping factor so often exhibited by SS amps. I strongly suspect your speakers exhibit dips in the impedance curve, which in combination with a so/so damping factor results in the lack of tautness. Different speakers, with a reasonably flat impedance curve and a sensitivity of 90 or so rate (IMO) to sound better.
All well and good, but you have to use 4 Ω speaker taps and derate the sensitivity. If you use 8 Ω speaker taps, the damping factor issue is made worse, along with providing an incorrect load.
Eli Dutman,
I bought a quad of matched Genalex Gold Lion EL84 tubes. Listened to these I must admit, after hours of listening: they are absolutely amazing!
Wonderful, airy, tight bass, beautiful midrange and extremely clean upperrange.
Voices are miraculous with lots of air around them.
Three-dimensionality is perfect! Even far above the loudspeakers you can "see" the music!
These tubes are great!
They are way better than the JJ-valves!
Very pleased with these Genalex Gold Lion EL84 tubes!
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