Hello Andy,
had you or anyone here the opportunity to use the Hashimoto H-30-3,5 (Hi B C-core)?
I'm planning to upgrade my AN Kit one that have the 152 OPT.
alguien tuvo la oportunidad de probar el hashimoto? But maybe the right comparison here is against the AN double C core improved Hi B, the cheaper of their double C core that cost the double than the Hashi, that is the regular kit one upgrade path.
Regards
Hi Andy..
I have a pair of summit S-9 on my 2A3 up running for 50 hours now.
I'm using Rod Coleman as you do, and as preamp it's 4P1L.
I cant tell about the Etude, but the Summits S-9 are amazing.
My 2A3 has had several upgrade but this is like getting a whole new amp.
Best Michael
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I might be in the market for some 300b opt soon, I built a little 300b amp a few years ago purely as I came across some unbelievably cheap tubes, started by rejigged a 6av5 se amp with transcendar 10w 5k opt and hi gm pentode driver triode strapped. Sound was promising enough to gut my gm70 amp for parts and went 4p1l filiment biased driver and lundahl 1620/120ma with 6ax5 full wave rectifier choke input p/s. Best sounding amplifier I've built for vocals and realism. I started changing it to bridge rectified 6ax4 and better power trans and oil caps from dry polypropylene. I'm getting back into the hobby so just started back on it and might get some decent opt for it to free up the lundahls so I can rebuild my gm70s. Lundahls were a noticeable upgrade to the transcendars. I bought some BIG Bezdz opt for my 833, per kg unbelievable value and very fast shipping but not hifi, going to do some work on that this winter and add a high gain driver to allow some feedback, -3db at 15k isn't enough even for my ears.
Sorry for the rambling, cutting to the chase, can I get anything better than my lundahls for <400 ukp ?
Enzo
Sorry for the rambling, cutting to the chase, can I get anything better than my lundahls for <400 ukp ?
Enzo
Slightly at a tangent, but I've been rebuilding my 4P1L amps and the biggest improvement has been the power supply. I decided to put all my best parts into one outboard power supply - two huge chokes (like BIG) and two AZ1 mesh rectifiers in parallel. It really made a difference.
The other thing I liked was going from a LL1660 interstage to a plate choke and teflon FT-3 cap. Slightly more extended treble and a nice clean sound. Not hugely better but I like it.
I'm still using a LL1620/80mA OPT in my PSE 4P1L. I have a single 4P1L SET with LL1682/50mA and that's really promising. I may investigate the LL1663. That's good value.
The other thing I liked was going from a LL1660 interstage to a plate choke and teflon FT-3 cap. Slightly more extended treble and a nice clean sound. Not hugely better but I like it.
I'm still using a LL1620/80mA OPT in my PSE 4P1L. I have a single 4P1L SET with LL1682/50mA and that's really promising. I may investigate the LL1663. That's good value.
I'm using the transcendar opt in a 4p1l filiment biased spud amp driven by a 4p1l preamp amp currently till the 300b is ready. It's 6ax5 bridge choke input power supply. I built it to test a few tubes Inc 6p21s, all at 230-50v. The 6p21s were good, but over the course of a few weeks they went downhill till they distorted badly so perhaps the rumours of short life are correct. Certainly had a more powerful driven sound than the 4p1l, perhaps due to the higher cathode current and power. I'm also using ft3 Teflon caps at the output of the pre. I find the sound good, but not as realistic as the lundahl'd 300b amp. My speakers are very efficient but a single 4p1l is borderline power wise.
I like the 4P1L sound - it's just great on vocals and piano, both of which are a lot of my listening. I originally had 2a3 and 300b outputs but this needed 3 stages, and when I replaced the 300b with 2 x 4P1L in PSE I found that 2 stages were audibly cleaner and more detailed.
I also am pretty much at full volume, but since I use a Mac Mini as source and volume control in software it suits the digital volume control to be near the end of its range. The other thing was that using filament bias everywhere removed the cathode bypass caps and that was a significant advantage in terms of sound. Right now I'm trying to find out just how good a 4P1L into 4P1L amp can sound by tweaking everything.
I also am pretty much at full volume, but since I use a Mac Mini as source and volume control in software it suits the digital volume control to be near the end of its range. The other thing was that using filament bias everywhere removed the cathode bypass caps and that was a significant advantage in terms of sound. Right now I'm trying to find out just how good a 4P1L into 4P1L amp can sound by tweaking everything.
Hi Andy.
A little off topic, but are you using your "newly" 4P1L SE as you primary amp now ??
http://www.diyaudio.com/forums/tubes-valves/183329-one-more-4p1l-se-95.html#post4462490
Still without any preamp ??
What is the wattage on this amp (2-3 watt) ??
Regards Michael
A little off topic, but are you using your "newly" 4P1L SE as you primary amp now ??
http://www.diyaudio.com/forums/tubes-valves/183329-one-more-4p1l-se-95.html#post4462490
Still without any preamp ??
What is the wattage on this amp (2-3 watt) ??
Regards Michael
I'm a big, and now probably not entirely impartial fan of Monolith Magnetics, they have done a number of custom transformer designs for me, and I am extremely pleased with the end results. I can recommend them without hesitation.
Hi Kevin,
I remember reading that you had experience with the top-line Tamura transformer and stated that it was the best that you had experienced.
We know that the price of both Tamura and Tango (Hirata) are essentially up for auction.
Would you be comfortable with sharing your opinion on the newer and above mentioned transformer WRT your memory of the Tamura unit?
Sincerely,
LH/S
Haven't measured actual wattage. In the 4P1L SE the output stage runs at 240v, 35mA and -19.5v bias. Should be a dissipation of around 8.5W, just under the theoretical maximum 9W adding grids 2+3 to the plate.
The PSE version is louder and more comfortable on a variety of programme material, as you would expect. I have no trouble with voices and piano with two 4P1L in sequence - as good as I've built in an amp.
I do have a little issue with violins - they can be a touch gritty. Haven't tracked down exactly why. I think they are a little cleaner on the single SE. Maybe some issue paralleling two 4P1L. Or it may be the input section is working at around 24mA with a beefier plate choke. In my PSE amps I'm still using 15mA plate choke (126C Hammond primary) or LL1660/18mA. Parts I just happened to have. Not ideal. The sound of the 4P1L can get a bit thin under 20mA. The Hammond 126B sounds as if it could be a good plate choke for a 4P1L, just using the primary which is gapped for 30mA.
I have four or five 4P1L amps which I rotate and rebuild. Trying to find the perfect alchemy!
I haven't used a preamp for a long time - not since I put all my amplification on one chassis and the power and filament supplies outboard on other chassis.
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I remember hearing that 4p1l into 4p1l had issues, I think it was probably either you Andy or Ale Moglia? You don't feel it's a problem? certainly sounds ok to me, thinner than 4p1l into 300b or more likely 300b is a fuller sound than neutral? It might be a power thing or output impedance but I find my version a little too smooth and lacking in thwak. 6p21s had it in exactly the same amp. I'm running them at 230v 30ma -15.5v
Looking at the 3.5K James Audio JS-6133HSF ($420/pair on ebay), specs say "100mA" and they weigh 11.5lbs. The 3.75K Edcor CXSE's ($175/pair) weigh 9.75lbs. and they are rated at 200mA. Surely there's a discrepancy there?
https://www.edcorusa.com/cxse25-8-3_75k
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Are those specs talking about the bias current before saturation?
Thanks,
Kevin
https://www.edcorusa.com/cxse25-8-3_75k
«¬ ¸¹ ªì¯ÅDC¹q¬y
Are those specs talking about the bias current before saturation?
Thanks,
Kevin
That's what I was thinking, it's hard to compare two apples when the one them is an orange.
I was assuming that the air gap would only help prevent but not eliminate saturation. I'm trying to choose a transformer for a tube that will be running near 100mA idle current and I don't know if a transformer that's rated at 100mA will work. Would one rated for 200mA be better?
That depends. You need to know the operating current the gap is set for. When it is set for 100mA than that's great and the transformer will work great with that current. If 100mA is the saturating current that's problematic.
If you need 100mA and use one for 200mA you throw away inductance.
Thank you, that's exactly what I needed to know. So, if the James Audio trafo lists the "primary DC bias current" as 100mA, then that means it was designed to work with a bias current at or around 100mA?
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In the case of a reputable manufacturer like James I think tht would be a fair assumption.
Magnequest are very conservative in their specification. From memory their FS-030 is rated at 65mA, yet is capable of passing significantly more current without saturation and deterioration of bass performance.
Magnequest are very conservative in their specification. From memory their FS-030 is rated at 65mA, yet is capable of passing significantly more current without saturation and deterioration of bass performance.
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