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Klipschorns with 300b amplifiers


sns109

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1 hour ago, Jeffrey D. Medwin said:

 

I've not owned all the speakers you mentioned Travis, so I am just speaking from deduction. 

 

Yes, if I had any  of those speakers, I would not be able to power them ideally with a state of the art low powered SE amp.  The low powered SE amp does not ideally match the Klipsch speakers' complex loads in my opinion.  The SE vacuum tube amplifier problem is the large Finals tube SE amps ( 300B, 211, 845, etc ) often are " clumsy " sounding to me,  compared to the smaller Final tubed ones. 

 

A decent tube amp for those speaker models you mention,  will be as described : a two stage directly coupled zero NFB Push Pull tube amp.  Maybe having 10 -15 Watts or so in power.  Chokes would be low in DCR, ten Ohms or less, and the amplifier would employ a LSES  all-film cap power supply and special B+ filtering techniques need to be applied.   

 

I envision this P-P amp for Klipsch speakers as per the topology schematic I posted last year, ( and referenced to ), in this thread.   No one has ever designed and built it. 

 

Jeff 

Well how much loss is associated with the AK6 network (that's the correct term for a "crossover"), or the AL5?

 

Don't the Sensitivity ratings for those speakers account for the "loss" resulting from the network?

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On 2/4/2020 at 8:58 AM, Jeffrey D. Medwin said:

 

 

Amp OFF, voltages drained.  Each lead of the choke, is connected to the positive lead of a supply cap.  Put the probes on those two caps - where the choke leads are attached to..  Ohms scale. 

 

EDIT on 2-6-20, 

 

The amp owner measured the choke at 111 Ohms, ..........over five times too high.

The wiring inside the amp is very poor IMHO, ...........as is every resistor..

Layout is sophomoric,, two-dimensional, not three, excessively long leads everywhere, tie wrapped together. 

Imagine an RCA Jack's input wires bundled and tie-wrapped together with the speaker leads, for about a thirteen inch span. !!!

Every cap inside appears to be an electrolytic, including Rk bypass caps .  We will decide in a week or two, what to do !!

 

You have incomplete knowledge. My Tube Fantasy 300B sounds terrific. You should actually listen to the amps before smearing them with your remarks. Must you shout by using a bold font? So what if the wiring doesn't have a bunch tightly twisted wires which just increases the length.

Edited by sojourn98
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Wait, so the wattage of the amp doesn't matter? I thought you said a 2 watt amp won't cut it because of losses. Did I get that wrong?

 

Is the "loss" some sort of frequency response, or instruments in the music diminish with a network?  Is this something unique to Klipsch, or with every speaker system that uses a network?

 

How were you able to avoid these losses with your network (below)

 

Where's @Deang to explain this?

 

 

EBkcNI8.jpg

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So Jeffrey, are you claiming that a 2 watt tube amp can deliver hundreds of amps of peak  current?  
 

Typical EEs would not find anything you said above to be reasonable because they understand electronics!  
 

Didn’t you once state on AA that your ears can’t hear much above 5kHz?

 

 

Maynard

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  • 1 month later...
On 2/2/2020 at 11:48 AM, sns109 said:

Hello, this is my first post, although visit these forums often. I recently acquired a 300B SET amp to audition as a summer replacement for my two 845 SET amps which are space heaters. Both of my 845 amps have wonderful tonal balance, articulate bass, reasonably extended highs, fully involving mid range. This is the third summer replacement amp auditioned, the first two class a/b solid state, both nice enough but lacking the palpable, meat on the bones quality of my SETs. The 300B has a nice palpable mid range, highs are a bit rolled which I can probably live with. The big issue for me is lack of articulation in bass, this along with more rolled off highs gives a rather dark presentation.

 

Overly loose, warm bass has always bothered me, articulate bass is an absolute requirement for me. I suspect a 300b amp may be inherently unsuitable for me. Looking at the impedance curve of Klipschorns, below 8 ohms between aprox. 40hz to 225hz along with steep impedance curve is too much for this amp. No separate taps on amp, assuming 8 ohm on non-separate tap tube amp. It seems the 845 SETs with their 8 ohm taps overcome this limitation, the 300b tube can't handle it. I'm in midst of one mod which may or may not address bass issue in that I replaced the Russian K40Y9 coupling caps with VH Audio Vcaps.

 

Assuming this 300b isn't satisfactory for me, what amps do you guys think would work for me? At this point I'm planning on auditioning First Watt J2 or F7, another intriguing option would be AGD Audion GaN Tube monoblocks, class D amplifier that supposedly replicates SET amp sound to quite a degree. The class A solid state amps will also be hot, albeit not to the same degree as the 845's. Any other class D amps close to SET sound?

Get rid of the crossover and biamp. Your 300B amp will like it and so will your ears.

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I have a PP 2A3 amp which gave me the umph I felt was lacking in the SET amps I tried (both 300b and 2A3).  I must admit the SET did have some really amazing "ghost" imaging I don't feel as strongly with my PP amp.  why not stay with the 845 SET amps?  warm regards, tony 

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19 hours ago, sunnysal said:

I have a PP 2A3 amp which gave me the umph I felt was lacking in the SET amps I tried (both 300b and 2A3).  I must admit the SET did have some really amazing "ghost" imaging I don't feel as strongly with my PP amp.  why not stay with the 845 SET amps?  warm regards, tony 

 

 

I have had many amps up to two watts. They do not all sound great. They need to be extremely well designed and the power supply is of the utmost importance. I don't have any EE in my background but I've noticed the better the power supply the better the SET amp. They also need a bit more refining. I built a 1625 triode amp and it sounded ok at first but not as nice as my 2a3/45 amp. My friend had me tweak the driver stage many times and it just went from an ok amp to great. I have several rebuilt PP amps EL37 7591 EL84 6L6 50CA10 2a3 but they just don't sound as good. The PP EL84 fisher is the best I've heard so far with the PP EL37 not far behind. What about higher powered SET amps 300b 211 845 ? I'd like to try a SET DC 300b/50 amp. However I think we are going to do a compactron 6HJ5 SET amp next.  The best amplifier with horns I've ever heard was a Eimac 75tl which was a bit higher power but that build is not for the faint of heart. Perhaps it is topology and execution that are of the most important.

 

 

 

 

 

 

 

 

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2 hours ago, seti said:

 

 

I have had many amps up to two watts. They do not all sound great. They need to be extremely well designed and the power supply is of the utmost importance. I don't have any EE in my background but I've noticed the better the power supply the better the SET amp. They also need a bit more refining. I built a 1625 triode amp and it sounded ok at first but not as nice as my 2a3/45 amp. My friend had me tweak the driver stage many times and it just went from an ok amp to great. I have several rebuilt PP amps EL37 7591 EL84 6L6 50CA10 2a3 but they just don't sound as good. The PP EL84 fisher is the best I've heard so far with the PP EL37 not far behind. What about higher powered SET amps 300b 211 845 ? I'd like to try a SET DC 300b/50 amp. However I think we are going to do a compactron 6HS5 SET amp next.  The best amplifier with horns I've ever heard was a Eimac 75tl which was a bit higher power but that build is not for the faint of heart. Perhaps it is topology and execution that are of the most important.

 

 

 

 

 

 

 

 


The question is what constitutes a better power supply for SETs.  If the ripple is sufficiently low to prevent any hum, all is well.  The DC current draw is almost constant in SETs, so regulation is often unimportant.  Of greatest importance is choosing an operating point which promotes the best linearity so distortion remains very low.  

 

Maynard

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1 hour ago, tube fanatic said:


The question is what constitutes a better power supply for SETs.  If the ripple is sufficiently low to prevent any hum, all is well.  The DC current draw is almost constant in SETs, so regulation is often unimportant.  Of greatest importance is choosing an operating point which promotes the best linearity so distortion remains very low.  

 

Maynard

 

Just reporting what I've noticed so far. The curious thing I've found is all distortion is not equal. I've seen some amps test horrible but sound good. I have a sound tech rack which I'm learning to use but it isn't the entire picture. Measuring wrong thing I suppose lol.... Getting there...

 

image.thumb.png.5e58d7d55ea4d13c07a13fd5d2eebebd.png

 

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  • 1 month later...

I've driven my LaScala's with various solid state amps and tube amps (PP & SE) and the LaScala's always sound great. Does the amp make the LaScala's sound different? Yes.

 

I guess it depends on the mood you are in and if you want to listen critically or just have background music. 

 

I have a Music Angel XD850 Mklll that has been redesigned (by me) and it has turned out to be one of my favorite amps - 6.5 watts/ch. It drives the LaScala's with ease and sounds great. No problem at all driving the speakers. However, I must emphasize that I am not using the original AA crossover, but a variation of ALK's universal heritage crossover. This will help keep the impedance constant and easier for the SE amp to drive.

 

I did not do a comparison with my modified crossover and the OE AA crossover so I do not have any comparison for that, but the new crossover does make an audible difference with tube or SS amps. 

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  • 1 month later...

I'm new to Khorns and I'm in the process of trying different amps to see what works best for me. The Art Audio Carissa Sig is an 845 based amp and it sounded wonderful with the Khorns. Prior to that an Aric KT 88 / 120 sounded quite nice but didn't have the depth of soundstage that I like. The 845 was great in that regard and the midrange was excellent. Bass performance was good also.

Next up is a pair of 300b amps that hopefully will arrive here on Wednesday this week.

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