Hello to all,
I'm just about pulling the trigger on ISO FC20s for a point to point Tubelab SE-II and am wondering if there are better irons for the same price or below available in Europe.
Monolith falls apart, as I'm not willing to pay that much.
How about the Lundahl's LL1620 or LL1623? Better bass response than the ISOs due their bigger physical design?
Many thanks and best
Ralf
I'm just about pulling the trigger on ISO FC20s for a point to point Tubelab SE-II and am wondering if there are better irons for the same price or below available in Europe.
Monolith falls apart, as I'm not willing to pay that much.
How about the Lundahl's LL1620 or LL1623? Better bass response than the ISOs due their bigger physical design?
Many thanks and best
Ralf
If you use the Lundahls of that series 1627, 1623, 1620, 9202....be prepared to limited high frequency response. They perform well at low frequency with low distortion figures but bandwidth is somewhat limited to 17-25 KHz depending on the model and application.
I had fair success with the LL1627 but any other transformer of this family I have tried has never won my vote. They have become quite expensive since I bought that pair of 1627's.....they are good products but nothing special.
The FC30-3.5 is more suited for the 300B.
The FC20 is ok for limiting cost but there is price to pay. It only weights 2 Kg...cannot expect high inductance, unless compromise all the rest which is not a great idea, IME. However it's good enough for sure. Despite the smaller size and limited inductance, I would take the Tango every time. Top notch in all other areas.
The headroom is enough for the average 7-8W 300B amplifier. Better used at 3.5K or 5K taps despite it only has 18H. For comparison to the Lundahl the power rating of the FC20s at 30Hz is 11W+ for 3.5K tap and 7W+ for 5K tap.
I had fair success with the LL1627 but any other transformer of this family I have tried has never won my vote. They have become quite expensive since I bought that pair of 1627's.....they are good products but nothing special.
The FC30-3.5 is more suited for the 300B.
The FC20 is ok for limiting cost but there is price to pay. It only weights 2 Kg...cannot expect high inductance, unless compromise all the rest which is not a great idea, IME. However it's good enough for sure. Despite the smaller size and limited inductance, I would take the Tango every time. Top notch in all other areas.
The headroom is enough for the average 7-8W 300B amplifier. Better used at 3.5K or 5K taps despite it only has 18H. For comparison to the Lundahl the power rating of the FC20s at 30Hz is 11W+ for 3.5K tap and 7W+ for 5K tap.
Don't buy the bigger Lundahls, they don't sound as good as the smaller models like the LL1663. I had a couple and sold them. My favourite Lundahl is the LL1682/50mA, which i prefer to the LL1664/70mA which I also have. Cleaner sound and generally better. I don't need much power, though.
Do you specially need deep bass? There are the big Hammonds for instance, but you lose the nice treble.
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Do you specially need deep bass? There are the big Hammonds for instance, but you lose the nice treble.
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Many thanks for the answers.
I'm mainly looking for an amp, that'll substitute my Aleph J clone sonically.
Important for me is a realistic presentation of instuments and voices.
I've build some PP tube designs in the past but never a SE. Therefore I rely on your judgements.
Would the step to the bigger Tangos or to Monoliths bring recognizable improvements or will they be on the smaller side?
I'm mainly looking for an amp, that'll substitute my Aleph J clone sonically.
Important for me is a realistic presentation of instuments and voices.
I've build some PP tube designs in the past but never a SE. Therefore I rely on your judgements.
Would the step to the bigger Tangos or to Monoliths bring recognizable improvements or will they be on the smaller side?
Realistic presentation....that's not where SE amps are famous for.
Substantial amount of second order distortion gives "big", "euphonic" sound, liked by many.
How realistic that is...hmmm.
What speakers would you drive with the amplifier?
Substantial amount of second order distortion gives "big", "euphonic" sound, liked by many.
How realistic that is...hmmm.
What speakers would you drive with the amplifier?
That hasn't been my experience. I'm a musician and I listen most of all to the timbre of acoustic instruments and voices and the overall clarity of the sound. Clearly, through years of practising, rehearsing and playing live I have a good idea of what real instruments sound like. I get all that with my SE 300b amp. It's taken years to work everything out, and it has massive power supplies and filament supplies full of chokes and regs, even though it's a simple 2 stage amp. Every part has been refined over the years, resistors, capacitors (teflon coupling caps), plate chokes (amorphous), OPTs.... everything.
The sound isn't "big" and it isn't "euphonic". It's very focussed, extremely clear, and the timbre of acoustic instruments is as realistic as I've heard on any system except big panel speakers like Apogee Duettas. These generalisations about "warm and euphonic" SE amps may be true of some, but certainly not when you come to very specialised builds with really good parts. Amps like this don't go loud and fill home theatre setups, but what they do - especially the instrumental and vocal timbre they achieve - they can do extremely well.
That is not true in general. I could build a 300B SE, 2 stages, with less than 0.2% THD at 1 W and 1% THD at 9W. Without feedback but only getting limited 2nd harmonic cancellation, between the voltage gain stage and the 300B, but still the typical triode distortion profile with dominant 2nd harmonic. It only requires some iterations to find the optimal balance and make it work....
Without cancellation, distortion was not that different up to about 3W output because of the intrinsic linearity of the devices. Cancellation only kicked in at higher power delivery.
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I think the FC20s could be fine. Build the amp for minimal distortion at low to medium power and it will be fine also at low frequency. If you use the 3.5K load 18H inductance is ok.