Capacitor experiences?

[SET12]

SpeakerFritz,

Thats alot of Spec's! And a very big chassis, I don't know anything about your age and experiance in audio!

But I will tell you a little more of my experiance I have been an Audio Buff for some 35 yrs I guess you can call me old school as in those days we only had 2-channel audio. My first amp was a phase linear 400 that might have been capable of 400 watts/channel, I then went to a Dynaco kit 400 I had lots of toys to go with it eq,noise reduction, blah blah.

Then I started thinking about true quality I steped into a Yamaha B2 and C2 and a Yamaha CT7000 the tuner alone in 1977 dollars was 1250$ it is the only piece I still have from that Era built like a Rolls Royce about 35lbs. The Yamaha B2 was about 135 watts/channel in 1977 I had a yrs wages tied up in my system.

Then I got into tubes in the early 90's via a friend, I was designing a solid-state buffered preamp and he asked me WHAT ARE YOU DOING? I took a book he had and designed a Vacuum tube buffered preamp. The fact that it worked! Drove me to go to a bar and by myself a drink! For me it was a milestone going back to the days of going to the local drug store to test tubes for my tv and old console reciever I had sitting on a piece of wood bare! at the time when the preamp was built I owned a Forte modle 4 power amp that had 50 watts/channel biased to 12 watts in Class A this was a 1800$ power amp. Which ended up going to the closet till I sold it after building this amp a friend brought over an old Pilot Integreated amp 20 watts /channel using a EL84 power tube he bought it for 200$. A vintage dealer told him it was fixed up to sound real good but when he got it home it sounded just terriable and he asked me if I could do anything with it I had a schematic for it and I saw a nice 2 gain stage amp that was just simplicty, So I bypassed the front end (preamp) as all the controls were diseased and made a power amp out of it he used it till one day his wife said it was BUTT ugly we had the back side facing front so you could see the warm glow! any way we restore the power amp using all the original Iron just spraying the Iron piano gloss black I designed a new layout on a piece of brass he made a walnut base for the brass plate we did it for 500$ DIYing it the result was a very entertaining amp that is still being used with Dunlevy 4's a 8000$ loudspeaker rated at 91 db efficiency we also later installed silver foil and oil coupling capacitors once in I was told I couldn't have them back! or my arm might be broken! My buddy is as big as a gorrilla!

The point I want to make is power corrupts and if the first watt doesn't floor you than the other 149 likely won't either.

Stereophile Magazine a few yrs ago conducted a lab test and proved that tubes have an overload charteristics that are much greater than solid state! for a push pull tube amp that is some 2 1/2 times greater than its continious power rating and for a single-ended amp it can be 5 times greater so my 10 watt peak (thats 5.5 watts RMS) its actually the peak watts of tube gear that have been compared to the RMS of solid state so my ten watts play like 50 solid state in loudness.

Most serious 2 channel friends of mine do not mix their 2 channel with home theater gear and some use their two channel gear with video but only in 2 channel mode many of my friends including myself just prefer the 2 channel after all most of my friends 2 channel systems far out weigh the quality of multi channel I use a seperate DVD player audio direct to my amp my sound stage is seriously huge! I find no need for a sub as my amps transit reponse can move the pictures on my neighbors walls and we are seperated by two garges I guess we found out that acoustic energy was traveling up my wall into the roof truss and back down into her living room. when I got her call I was playing some Jazz! this was after a 50 cent modification to my amps that made them ballistic!

Anyway I got to get some sleep I work nights I'm going to put a picture of the Brass Amp in here in a moment! See you L8ter!

SET12

[Guest " "]

If you really are old school, you will get a kick out of this link...get ready for a trip back in time.

http://www.dynakitparts.com/

35 years ago....lets see, yes I was an audio buff....I was repairing tube equipment at a local hi-fi and TV repair shop.

how old you ask...well when I was repairing tube equipment 35 years ago, I was 13. Built my first set of 3-way speakers (cabs, xovers, driver selection) a few years earlier at age 11.

[SET12]

Thanks the great link! Its nice to see these kits being offered I got a real kick out of the ST35 my daughter and I could put that one together she is 10 yrs old but very smart maybe in 1 or 2 yrs I could teach her to solder!

Since you have worked and repair tube gear. Can you design as well? These are my amps, the output trannys in the pics are just 6lb and are not the current 28lb ones I use now. Also the tube you see lit is a 811-10 which is interchangeable with a 572-10 which has a graphite plate for even better sound in my opinion.

[Guest " "]

Complete kit approach with your daughter is a great idea....clear instructions...specific goal...and path to achieve. Hey, call it an IPOD amp and your probally get her attention.

Deisign from the ground up is a lot furthur down the road than repairing or assembling.

I'm looking into putting together a tube amp...still undecided on the technology/platform, but will problally buy a complete kit from a company simular to the link I provided.

I might list all the mods folks are doing to their ST-70's and determine if it will make any sense to incorportate during the intial build.

[SET12]

Thanks for the tip thats an excellant idea! I look so forward to the day that I can share a building experiance with her if she wants to I don't want to push her of course but she does love music at least!

I have a bit of experiance with the 70's there isn't alot of room with them but the 70 is certainly one of the most moded amps around. I really like my friends Heath kit W5 mono's alot! some of which were came with Peerless Outputs check it out I think even in its stock form it is extreamly good and they will run circle around a stock 70 big time! and it is a Williamson circuit if you go to the Heath kit site you can even look at the construction manual and it has alot of great imformation on its design and why plus the chassis is as big as a 70 and it is all point to point wiring my buddy uses these with his LaScala's and just loves the bass produced from the W5. Scratch building does take more time but I think it can be more rewarding! Most of the time is devoted to layout and metal work, I made drawings and then templates for drilling so I could easyly reproduce the project.

Since were talking about caps I like to show you my Moving-Coil Phono Preamp it is two box's one is the supply and the other is some more supply and the circuit module tha is easyly removable to work on it has 3 gain stages and a split RIAA network with super overload capacity and most people know that electrolytic caps in volume as great as this usaully sound really bad but I discovered a way part by acident and part by design on how to get strikeingly transparent sound from something as large as this when I say transparent I mean like a high quality polyprop supply plus its speed I have 66db of gain with it from 6922 tubes and it is nearly dead quite. I was told by a local 35 yr High-End specialist that it couldn't be made quite.

[Guest " "]

I'm assuming all these caps are on the power bus.

looks like a first order ripple filter.

Have you looked into putting inductors in-line with the power bus between the caps and the load....2nd order filter

it could help reclaim some space by reducing the amount of capacitance needed for the filter.

just a thought.

[SET12]

You put a nice smile on my face speakerfritz! Thanks and I will always welcome your thoughs! and no it is not a first order it actually is an 11 section pie filter with each of the last 3 sections feeding a prop cap an Aeon to be exact. I can not go into alot of details about what is going on because this technique that I use may have a chance at a Patent.

When I concieved this supply circuit I thought I might be a little nuts! But I ran into a guy at a consumer electronics show in Chicago he was just 25 I think at the time. That man was Jim White whose company is Asthestix I don't think I'm spelling it right but his phono stage inspired mine and from the pictures of his I was able to reverse engineer a bit of his supply and found that his is as large as mine. I read a review of his and of course it put a smile on my face because his phono as dynamic as it is has a dark character to it and I knew at once why! Where as my phono is lit and holographicly vivid.

I once cut out half of my supply to hear its effect and I could hardly believe it but it was audiable in the sense of wieght though most people logically look at this thing as real overkill! But as I said the time constants are lightningly fast and yet this is not a regulated supply you need bulk if you are going to have low noise and speed at the same time and remember there is some 90db of gain minus the RIAA network so you have size to have speed.

Chokes are good and bad! the bad is the DCR and when the supply is being modulated the ACR.

Hears an example the brass amp, The circuit once had a 100 ohm resistor between the rectifier cap and the plate supply cap. My friend and I were listening to his ProAc Reponse 2's a hungry speaker with a 20 watt amp! Anyway I decided that since the amp was push-pull and we up'd they supply capacitance by a factor of 6-7 times I bypassed the 100 ohm resistor and we gave it a listen! He looked at me and I looked at him and he told me if it got any better he was going to cream his pants! And we never looked back! Now take a dyna 70 it has a 1 henery choke with a 60 ohm DCR, Do you get the picture? If the supply is 5 or 600 uf for the plate supply it may be enough for a 70 to try this. Also I'm no Ultralinear fan try listening to a dyna in Pentode mode the dynamics are greater! I will be designing an 833 amp in the future and it will Idle at some 300ma so I might have to use a choke but if I do it will be minimal like 1 henery with a DCR of just 5 ohms and the one I will use goes some 17lbs the key here is most people design with to big of values henery's, the Dcr is more important for speed.

My moto's with this Phono Stage are two with all the other big dollar phono stages looking at mine and saying " I fear all we have done is awaken a sleeping giant and fill him with a terriable will of resolve" another to describe the transit response is "if a fly lands on the input the Earth will move"

SET12

[Guest " "]

intresting....you don't find power resistors inline on the power bus on SS equipment. during the early 80's built a dyanco amp that had nice caps on the power bus. there was an inductor in-line with the cap and the load. the inductor was made of a fairly long lenth of wire wrapped around the power capacitors.

[Erik Mandaville]

Really great work -- thanks for sharing this! The work is just superb. We have some really valuable sources of knowledge and experience on this forum, and I'm willing to bet your daughter will pick up soldering very quickly!

On the capacitor question: Hovlands are well made capacitors IMO, but I have also found them to sound thin. However, they are still cheaper than the Mundorf variety. I also agree that the possibility for an active crossover approach starts to come into sharper focus when we get into these extreme costs of passive parts.

Something I have proposed in the past, which you might like to try (no doubt you have the technical ability to do it -- it's fairly easy, really....) would be to set up a network with a few different capacitor types/brands of the same value, with special attention given to the tweeter branch of the network. These caps could be switched in and out of the circuit (by way of a switch on the crossover board), and give you the chance to directly audition a few at a time. I don't believe that there is always a direct correlation between cost and performance, and I've even had very good results with extremely inexpensive mylar capacitors. Another option would be motor-run poly/oil type capacitors. They are most certainly NOT a compromise in either construction or audio performance. I am very happy with the inexpensive, well-performing Solen capacitors (those with the black insulation).

Good luck,

Erik

[SET12]

Hi Erik,

Thanks for the kind compliments!

How do you like your tube gear! Especialy your 300B's? Have you ever tried LED biasing? I have in several projects and likely will never go back to resistors the differance is very audiable akin to battery bias.

I'm from Appleton, Wisconsin some 25 mi from Greenbay WI I saw a thread on some guys from Milwaukee getting together I haven't tried to contact any of them yet I belong to a club here called NEWAS and we hold meetings at each others homes as well it would be cool to hook up with some of these guys from Milwaukee as I am the only NEWAS member with Klipsch's.

Here's a link to the NEWAS site if you'd like to take a look I have a thread called 833 amp with alot of interesting links to tube gear as well as transmitting triode amps like an 833 I am known as just SET on the NEWAS forum site.

http://newaudiosociety.com/cgi-bin/yabb/YaBB.cgi?board=amp;action=display;num=1137773606

Again thanks for the comments

SET12

[Guest " "]

////////////////

How do you like your tube gear! Especialy your 300B's? Have you ever tried LED biasing? I have in several projects and likely will never go back to resistors the differance is very audiable akin to battery bias.

//////////////////////////

LED biasing...intresting.....I did some work with battery biasing during the early 80's with some dynaco SS equipment and was impressed with the results.

[SET12]

I was reverse engineering a Phono stage and noticed some diodes they were barrier diodes that produced .410 volts forward biased with 1 ma. of current flow LEDS are better but use small sizes for small currents their voltage variation is less as well.

When I saw the diodes I took them out and replaced them with resistors with bypass caps, The sound differance was amazing! As fast as I took them out as fast as I put them back and I have never used anything but diode biasing that experiance!

You can use a small bypass cap to help with its high frequency AC impedance it depends on the tube used most of the time none is really needed. And of course you can't use it in a feed back loop. I use diodes with directly heated Triodes as well and "WOW"

SET12