I think my System is virtually, finally finished

[P.I.]

One other tidbit if I may.

It is almost always advantageous to use the same brand, and even model, capacitor throughout
a design. When one has to compensate an inferior capacitor with a different
brand capacitor, the end result is almost always degraded sound in one or more aspects.

Using the same brand, the most natural/accurate capacitors in a design results in fewer abnormal
aspects in sound. Of course, the budget needs to be considered.

As an example, adding a single 1ufd solen capacitor into the crossover network negatively affected
the sound of the entire system.

One outstanding, natural, accurate capacitor, in absolute terms, is the Mundorf M EVO aluminum,
in oil (white covering). Small to large values I have tested are outstanding and recommended.
(I am not affiliated, and/or compensated in any way from Mundorf.)
 
cheers

steve

I have found capacitors made by SCR (Solen, Axon, etc) have a house sound: gritty 🫤 . 

I'm in absolute agreement about using the same cap family in gear for consistency.

[steve]

One other tidbit if I may.

It is almost always advantageous to use the same brand, and even model, capacitor throughout
a design. When one has to compensate an inferior capacitor with a different
brand capacitor, the end result is almost always degraded sound in one or more aspects.

Using the same brand, the most natural/accurate capacitors in a design results in fewer abnormal
aspects in sound. Of course, the budget needs to be considered.

As an example, adding a single 1ufd solen capacitor into the crossover network negatively affected
the sound of the entire system.

One outstanding, natural, accurate capacitor, in absolute terms, is the Mundorf M EVO aluminum,
in oil (white covering). Small to large values I have tested are outstanding and recommended.
(I am not affiliated, and/or compensated in any way from Mundorf.)
 
cheers

steve

I have found capacitors made by SCR (Solen, Axon, etc) have a house sound: gritty 🫤 . 

I'm in absolute agreement about using the same cap family in gear for consistency.

Nice way of putting it Dave. Same here, gritty, which, for newbies, means the harmonic structure
of the instruments/voices has been slightly altered, and different from, say, the M EVO Mundorfs aluminum.
I mentioned this aspect because on other forums I have read some trying to improve
synergy by using different brand caps. Better off to improve the overall design.

cheers

steve

[steve]

Just want to invite anyone traveling/living near Morton/Peoria, Illinois to drop by and see what I am testing
at the moment. Please give 1 days notice if you can so I can get the system warmed up.

Just PM me or use stevesammet at yahoo.com

Cheers

steve

[Nick B]

Just want to invite anyone traveling/living near Morton, Illinois to drop by and see what I am testing
at the moment. Please give 1 days notice if you can so I can get the system warmed up.

Just PM me or use stevesammet at yahoo.com

Cheers

steve

Hi Steve,

Too bad I live so far away, or you'd have a squatter on your hands for a brief time  😁  Sounds like great fun!
Nick

[P.I.]

Just want to invite anyone traveling/living near Morton, Illinois to drop by and see what I am testing
at the moment. Please give 1 days notice if you can so I can get the system warmed up.

Just PM me or use stevesammet at yahoo.com

Cheers

steve

Hi Steve,

Too bad I live so far away, or you'd have a squatter on your hands for a brief time  😁  Sounds like great fun!
Nick

Yes, it does!

[steve]

I found out (probably should have known) that the JJ output tubes use solder without lead
in the tube pins. Unleaded solders tend to thin the sound vs quad solders with lead.

So I added some quad solder to the cathode, grid, screen, and plates pins of the KT88s. The sound
did fill out a little. I like both the JJ KT88s and the new Tung Sols (given to me years before the war).

I am also testing lower filament voltage and its effects on life on new, small signal tubes. In general
there are several causes of reduced tube life.

1. Residual gas/ ion bombardment
2. Too high of filament voltage "boiling" off of oxides
3. Too low of filament voltage causing excessive space charge depletion
4. Cathode sleeve impurities causing poisoning of the oxides

It may or may not take some time of use to hopefully arrive at a conclusion or two.

Cheers

steve

[steve]

I posted this in another string but I feel it is very important as tubes are getting
quite expensive, especially NOS.

This is not a truly representative test as only 1 used JJ E88cc tube with two sections,
A, B are being tested. I will have to perform more tests with more JJ E88cc tubes for
better overall accuracy but should give us a good indication. Tube has been turned
off just a couple of times so far.

Test started on 8-11-24, measurements below are from 8-15-24.
Very early on, approximately 90 hours, the tube appears stable.

I did make a change from 2 watt to dual 12 watt plate resistors on 8-11
for increased heat related stability. Different RL resistance values A and B
are due to availability from the old parts box.

RL A are two Mills 12 watt resistors in parallel for 7.11K ohms
RL B are two Mills 12 watt resistors in parallel for 7.71K ohms

Voltages and currents are approximates.
           
Filament                  5.85 volts dc

B+ voltage              142
Plate A voltage        71.8 volts
Plate B voltage        63.8 volts

Plate A current         9.86ma
Plate B current         10.13 ma         

We'll see how the tube acts over time.

cheers

steve

[steve]

Hear are some results after ~ 450 hours using a used JJ E88cc tube, at ~5.85 filament volts.

The AC line voltage varies slightly, which I can adjust, so there is only a slight DC voltage variations,
but not enough to cause a problem. I can adjust the line voltage for exactly 5.58 filament volts at
measurement times. Military Grade Mills RL's A and B values remain stable since the dissipation 
is only ~0,7 watt dissipation vs 24 watt rating.

Filament                  5.85 volts                  5.85 volts

B+ voltage              142 volts                   141.7 volts
Plate A voltage        71.8 volts                   72.2 volts               
Plate B voltage        63.8 volts                   63.7 volts

Will continue to add hours, and will check in later.

cheers

steve

 

[steve]

Hear are some results after ~ 450 hours using a used JJ E88cc tube, at ~5.85 filament volts.

The AC line voltage varies slightly, which I can adjust, so there is only a slight DC voltage variations,
but not enough to cause a problem. I can adjust the line voltage for exactly 5.58 filament volts at
measurement times. Military Grade Mills RL's A and B values remain stable since the dissipation 
is only ~0,7 watt dissipation vs 24 watt rating.

Filament                  5.85 volts                  5.85 volts

B+ voltage              142 volts                   141.7 volts
Plate A voltage        71.8 volts                   72.2 volts               
Plate B voltage        63.8 volts                   63.7 volts

Will continue to add hours, and will check in later.

cheers

steve

9-28-2024   ~600 hours

Fil voltage                          5.85 volts

B+                                  141.2 volts
Plate A Voltage                 72.9 volts
Plate B Voltage                 64.3 volts

Voltage changed slightly but within 2%. Will continue.

steve