Resistors suggestions for Boozehound Jfet phono pre, etc.?

[The Space Egg Corp]

PSU's...well...

No real need for chokes if you make a shunt-regulator...
...which is probably best for long term ease of use & max low impedance power.

However...
...Batteries are always an option, for those who want to get started quickly, or who don't want to mess with mains-voltage, or complex regulators.

Just worked out the power consumption for 'AA' & 'C' type batteries ( aprox. )...
16x 'AA' cells in easy fit 2x 8 battery holders...About 65 hours play time.
16x 'C' cells in easy fit 4x 4 battery holders...About 195 hours play time.

Of course if you have a couple of cars sitting in your drive...
...& some jump-leads...
...just connect the 2 auto batteries in series...& power the Boozehound from that !!!

Now there's a VERY low impedance power supply !!!

You could remove the batteries from the cars & plonk them down on the living room floor...
...The Misses ( based on experience ) may not like this...
...No problem...
...Just tell her Madonna will sound WAY better with the auto batteries...
...simples...
...JOB DONE !

Si.

PS no need to run the auto motors whilst playing...
...could cause system interferance...
...not absolutely sure...
...but my guess is you could probably power a Boozehound for 5 years this way, on 1 charge !!!

( hook up solar-panels...for an environment friendly Boozehound )

[audio mind]

Never been a fan of batteries, yes they are very quiet but usually when I have tried them they sound either wimpy or dark to me plus it really bothers me that are always running out of juice. The sound doesn't just cut off it gets progressively worse, in electric cars it is called range anxiety and a large part of the reason we have hybrids and not pure electrics.

Also I heard difference in sound quality between brands. More testing I don't really want to do. By the way I found the cheap crap short lasting non alkaline batteries sounded less harsh than say Energizer, although Duracell was not too bad.

Ok I'll stop whining now and say I would be a little more open to trying the car battery though. I have one from a Mazda Miata so it is not too big to sneak in the living room and I can use a charger when I am not listening to keep the volts up.......hmm worth a try, I am always willing to try an untested scenario.

[The Space Egg Corp]

Some 'L' Pacific' Build Photos.

Note these are all from some years back...before the 'vogue' for ex-soviet military hardware capacitors.

They all use the same, small red, low-voltage polypropylene types for the EQ section & coupling capacitor.

Some of the schematics posted on the last page are quite clever...
...in that they have optimised the EQ capacitor values, using an RIAA calculator...
...and come up with 99nF Bass, 33nF Treble, 66nF Coupling...
...pretty smart...just buy a big bag of 33nF caps...measure & match them...
BINGO

33nF x 3 = Bass 99nF
33nF x 1 = Treble 33nF
33nF x 2 = Coupling 66nF

Perhaps a few polystyrene's or silver-mica's added later for fine tuning of the RIAA values.

Neat.


Si.

Here's the build photos...Mad_K's is the first one...
...Mads, love your building style dude...your BZLS is a masterpiece also...
...a fan

[williamsunique]

I am using optical resistors in positions R1 and R9. See https://picasaweb.google.com/udailey...at=directlink#

Paul.

[erin]

Originally Posted by The Space Egg Corp

My favorite 3watt wire-wounds BTW are...

...the green-round type 5% £0.50p each

I think you are talking about Welwyn W21, and yes, they are very good sounding resistors.

[audio mind]

Erin, have you compared the Welwyn W21 to Mills or any other wire wounds?

[erin]

I have compared them to generic white square body wirewound resistors and the welwyn sounded better. I have compared Welwyn to other metal film resistors like Dale, Philips, Beyshlag, even Vishay naked, and I find Welwyn to have a much clearer sound across the entire frequency range than any metal film resistor, they also have really good HF extension and clear deep bass. Perhaps Mills might be better, but I didnt try them.

PS> I'm now waiting for a troller to tell us that all resistors sound the same. Hopfully the trollers will stay away.

[audio mind]

Wow! Thanks for the heads up, if the Welwyn W21 even is comparable to a Vishay nude that is saying a lot. I must give those a try as the price is mere pennies next to the Vishay.

I have actually given a good deal of thought lately to those who say they can't hear the difference in resistors and other component changes and I believe I have some sincere answers.

I am not trying to ruffle feathers but only to possibly shine some light for those in the dark to experience the fun (or madness!) some of use are having. Sorry if this is rambling a bit but I found writing this to be more relaxing than watching TV.

1.Check your hearing and your gear-

There are quite a few on line tests if you don't have a tone generator or test cd. The link below has a test that goes from 20-20k, don't use the ones that only go up to 8k as they are good enough for speech but not quite so good for your hi-fi purposes. You will also want to do a search for other online hearing tests that use several different methods of testing such as speech and back round noise.

What is your hearing range? | egopont

If you are not hearing as high as you thought you could, try a few different sets of headphones, instead of speakers.

I can hear up to 19k on most headphones and on a set of ADS speakers that have 3/4" tweeters on my pc. The ADS 3/4" tweeters are supposedly good up to 27K from old spec sheets. I find most speaker companies with 1" dome tweeters just say their speakers go up to 20K for marketing. Your average hi-fi speaker actually trails off around 16-17k being quite a few db down at 20k from my experience unless you have ribbons or some exotic tweeter. I have tested many really expensive tweeters, few make it flat to the top in reality.

2. Try changing a resistor that is directly in the circuit path on a design that is fairly simple. Also try wildly different types of resistors, like a vintage brown colored carbon comp to cheap blue metal film. Low parts count designs are much more dependant on a single component that one with hundreds of resistors. If you are willing to spend a few dollars try a couple of Caddock TF020 or MK132 and or a Vishay nude versus cheap radio shack blue metal films or carbons. There is an absolute huge difference in sound that some may or may not like. The point is the difference is huge and most people with decent hearing should be able to easily tell the difference between the cheapo's and the some of the most pricey, in the circuit path on a low parts count design.

3. Some of you may have not even attempted trying to hear the difference because some audio intellectual authority figure in your life claimed there was no difference and this authority figure may have a doctorate or high level of engineering education, so they must know what they are talking about and you don't even try.

Well I am telling you as a very experienced recording engineer and audiophile (folks this is a rare combo if you didn't know) that these supposed "learned" people are like virgins telling you they know what sex is about because they read a book. Give resistor testing a try if you haven't actually done so, it may open up a whole new world for you.

4. Have a test that allows you to switch instantly back and forth between the two types of resistors.


5. If all this fails, try the resistor change back and forth test on a small simple tube amp using quality horn speakers, or maybe even some decent quality pa speakers (decent folks, not rolled off honking junk) with a compression driver horn mid and/or compression horn tweeter might do the trick if you don't have access to a high quality horn hi-fi speaker. For some of you it will be a revelation for sure if you have not heard the synergy tubes and horns have. Might change your view of hi-fi completely, the harsh horns suddenly are not so harsh but alive!

[erin]

Well said

[audio mind]

Originally Posted by williamsunique

I am using optical resistors in positions R1 and R9. See https://picasaweb.google.com/udailey...at=directlink#

Paul.

I looked up "optical" resistors and there was not much info. Apparently they are also called "photo" resistors and there was quite a bit more info.

In the recording studio an optical compressor is one type of audio compression device that uses a photo sensor to reduce level. They are noted for a very smooth level change. I never closely studied the optical design so I didn't realize the optical device was a resistor.

Well how do the optical's sound or don't sound in a conventional audio circuit as a fixed resistor?

I was having trouble finding values under 2k where do you get yours?

and it the specs were a little strange compared to conventional resistors, do they all change resistance or something when light is applied? Do you need a light to operated them?

Wiki definition:photoresistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity; in other words, it exhibits photoconductivity.

Thanks for the input.