Tube curious

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mick wolfe

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Re: Tube curious
« Reply #40 on: 12 Sep 2024, 04:59 pm »
Hardly could consider a Dynaco end-game in terms of sound quality, its a PCB Push-Pull Pentode amp, perhaps end-game in terms of options, but it have a quite different sound from a Transistor Class AB amp.

In the mid 1990s a late friend (RIP) Opera/Classical music fan bought one Dynaco 70 EL34 to drive his JBL L90 4ohms 90dB and his original EL34 tubes lasted only 6 months, so he sold the Dynaco and returned to one of his Sansui/Technics integrated amps.

A modern ST70 from builders like Kenny Russell, Will Vincent, VTA, etc. can certainly be end game for many. This especially for those trying to achieve the best sound within a given budget. The key being NOT to pair it with a 4 ohm speaker (I assume nominal) like the JBL mentioned. The magic of a tube amp like the ST70 is best realized when paired to a speaker with a benign impedance curve that stays above 4 ohms throughout the frequency range. In regard to speaker wire and tube amps, I've used ribbon, solid and stranded over the years. They've all worked fine :scratch: Pick the one that best fits your ear and system.

FullRangeMan

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Re: Tube curious
« Reply #41 on: 12 Sep 2024, 07:21 pm »
A modern ST70 from builders like Kenny Russell, Will Vincent, VTA, etc. can certainly be end game for many. This especially for those trying to achieve the best sound within a given budget. The key being NOT to pair it with a 4 ohm speaker (I assume nominal) like the JBL mentioned. The magic of a tube amp like the ST70 is best realized when paired to a speaker with a benign impedance curve that stays above 4 ohms throughout the frequency range. In regard to speaker wire and tube amps, I've used ribbon, solid and stranded over the years. They've all worked fine :scratch: Pick the one that best fits your ear and system.
I understand your point, in the hey days of flea power tube amps the speakers were all 16 ohms.

opnly bafld

Re: Tube curious
« Reply #42 on: 12 Sep 2024, 11:58 pm »
Many Magnavox console single ended amplifiers from the hey day work best (more power/EDIT less distortion) into 4 ohm loads.





There are many vintage and newer tube amplifiers that work fine with 4 ohm speakers.
« Last Edit: 14 Sep 2024, 01:11 pm by opnly bafld »

FullRangeMan

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Re: Tube curious
« Reply #43 on: 13 Sep 2024, 12:02 am »
Many Magnavox console single ended amplifiers from the hey day work best (more power/less distortion) into 4 ohm loads.
There are many vintage and newer tube amplifiers that work fine with 4 ohm speakers.
:lol:

theflattire

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Re: Tube curious
« Reply #44 on: 13 Sep 2024, 02:19 am »
Check Analog Ethos.
I built the Legendarium and was very happy.

opnly bafld

Re: Tube curious
« Reply #45 on: 13 Sep 2024, 03:38 am »
Check Analog Ethos.
I built the Legendarium and was very happy.

Excellent suggestion, Perry has nice kits and sells fully assembled amplifiers including a new ST-35 inspired amp.

/mp

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Re: Tube curious
« Reply #46 on: 13 Sep 2024, 02:48 pm »
Tubes work with high voltage and the thin stranded wires will oxidize in short time with the passing current, but stranded wire is the darling of builders why it is easy to solder and Hard Wiring are very difficult to solder.

This is only at the trimmed ends or is the insulation (slightly) porous to air?
 

opnly bafld

Re: Tube curious
« Reply #47 on: 13 Sep 2024, 05:46 pm »
This is only at the trimmed ends or is the insulation (slightly) porous to air?

The original stranded wire in my 60+ year old Magnavox looks brand new.

FullRangeMan

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Re: Tube curious
« Reply #48 on: 13 Sep 2024, 11:21 pm »
This is only at the trimmed ends or is the insulation (slightly) porous to air?
Hi MP,
Please excuse Opnly Bafld provocative and clearly wrong posts,
please disregard his latest couple statements.

In the mid 1990s appear a regular audiophile at a local dealer with a PP PL519 amp with allegedly 7-8 years old, the internal wiring was stranded AWG 14 and 16 PolyPropyline jacket what is nice, some wiring was with the copper tarnished at the ends and there was verdigris/green rust on the ends.

I suggested him replace the corroded wiring with enameled magnet wire, unfortunately he could not find a technician willing to solder several rigid wires in a small space inside the chassis, so I made the mistake of offering to do this job, result that one week later I returned the amp to him, in one full week I managed to replace only 4 wires in the amp.

So I really hats off the superb Chinese workers who weld hard wiring like the Prima Luna and Ming Da folks at China  :thumb:

opnly bafld

Re: Tube curious
« Reply #49 on: 14 Sep 2024, 01:58 am »
Quotes from Dave Gillespie referring to the Magnavox 8600 6BQ5 SEP.

"Using a a proper 4 ohm load and a mid band frequency of 1 kHz, each channel could develop just 2.3 watts of power before (unequal) clipping commenced."

"Here channel 1 trying to develop 1.35 watts into an 8 ohm load at 1 kHz. Clipping is obvious,..."

Don't know Dave G?
Do some easy research, he has imparted more tube amplifier wisdom in a single sentence than some have their entire life of armchair typing.

Ever see any tube amplifiers with 4 ohm taps? Why do they have them?



A couple of weeks ago I had to move a ground in my ancient Magnavox to fix a hum and I cut the wire stripped it back a little and soldered it in a new location, the old wire was perfectly good to do its job. Countless people (like me) have refreshed tube amplifiers built decades ago and they put in new caps and resistors, but most leave the wire original. Why would they do that? Why do so many experienced amp builders use it? Because they know it does the job and will outlast them.

FullRangeMan

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Re: Tube curious
« Reply #50 on: 14 Sep 2024, 05:44 am »
Quotes from Dave Gillespie referring to the Magnavox 8600 6BQ5 SEP.

"Using a a proper 4 ohm load and a mid band frequency of 1 kHz, each channel could develop just 2.3 watts of power before (unequal) clipping commenced."

"Here channel 1 trying to develop 1.35 watts into an 8 ohm load at 1 kHz. Clipping is obvious,..."

Don't know Dave G?
Do some easy research, he has imparted more tube amplifier wisdom in a single sentence than some have their entire life of armchair typing.

Ever see any tube amplifiers with 4 ohm taps? Why do they have them?



A couple of weeks ago I had to move a ground in my ancient Magnavox to fix a hum and I cut the wire stripped it back a little and soldered it in a new location, the old wire was perfectly good to do its job. Countless people (like me) have refreshed tube amplifiers built decades ago and they put in new caps and resistors, but most leave the wire original. Why would they do that? Why do so many experienced amp builders use it? Because they know it does the job and will outlast them.

Many Magnavox console single ended amplifiers from the hey day work best (more power/less distortion) into 4 ohm loads.
There are many vintage and newer tube amplifiers that work fine with 4 ohm speakers.
Your claims as (more power/less distortion) are beyond the laws of physics.
This 1kHz sinus wave dummy load test mentioned does not corroborate your miraculous amp to music. Dont believe everything you read on the internet.

opnly bafld

Re: Tube curious
« Reply #51 on: 14 Sep 2024, 02:03 pm »
I edited reply #42 above; power is higher and distortion is slightly higher into the proper load versus a higher impedance with lower power and lower distortion.
The post was made in haste  :oops: , I have known about light loading and lower distortion for a long time thanks to Roger Modjeski.



Interesting video about a low wattage tube amplifier's power and distortion into resistors vs a speaker (Magnepan 4 ohms  :o ).

https://www.youtube.com/watch?v=CwTigvF0-Ho