[Texasrocker]

I figure this forum has some interest in high-end tube type audio products from yesteryears,and also enjoying restoring them?
I still enjoy saving all brands old tube-type radios as well !, but recently have been recreating some "groundup" projects building custom vintage hifi amps, 50s era rec-studio quality tube comp/limiters etc., utilizing some vintage recently acquired vintage 40s/50s era "heavy iron" power trans, & vintage high-end type " linear" output trans. I recently acquired 3 pairs of vintage Heath W5Ms (williamson types rusted chassis), and several other brands to use good spare trans off of to "create" in the full 20-20khz spectrum, altho, human ears can never tell the difference most usually anyways.
One caveat, ... Im using all DC powered tube filament supplies in my one-off creations in my "homebrewed" preamp sections, to meet RIAA standards for those with better ears than me, utilizing various new NTE bridge rectifiers for no-noise, quiet preamp solutions in all vintage tube equip resto one-offs, to rid any ear-fatigue that is now present in our new "digital" world!Tubes just sound better/ & warmer to the ear overall!! Just my .02! I figure I can re- install all these vintage, rare I/O type peerless brand trans, as well as many other brands "audiophool" quality trannys to good use in my projects over time.
I am also stripping-off previously rusted integrated tube type chassis from many yrs storage, by vintage mfgrs such as Sherwood Labs,Heath, Eico,etc. The old vintage Dukane,Bell,RCA,Gates,Altec, US orig JAN military spec etc, vintage WW2- 60s era amps components are all still good also. Much different area of tube type restoration indeed, but all theories apply! Even the old orig oil-filled electrolytic caps still test good! I wouldnt be afraid to put them in service again at all! Dont tell the "green peace liberal guys", but I suspect all these old oil filled caps contain PCBs? Whoa pardners!! No wonder they lasted so long! ( hee hee) Some things just "work" forever!!
Lordy mercy,all the old vintage Telefunken & Mullard , vintage RCAs,etc branded tubes I now have in backstock ( found in all these old sets), yet to be tested, will take awhile indeed! Tone, Tone maximus if still good also.
Hifi'ers, any out there? Theres still great barn-finds out there indeed, even if the roof leaked!! Lots of yellow-jackets nests in all this old equip also! I found a lizard skeleton in a vintage early 60s Sherwood S-5000 chassis, but the orig Sherwood Labs " hand-wound" trannys are still perfecto indeed! Not that most human ears will ever notice the difference anyways! This is a great hobby!!

[kruc]

I guess I fit that category, however I use new components when I build something. I've been building a 300B amp since last winter, though I got sidetracked with rebuilding a Philco 20 and now a 71. I saw a plan I could copy on the web, sourced the parts, laid out a 1/4" aluminum chassis and had it powdercoated, started soldering, and then read a post on a forum from the builder that he never could get the hum out of the design. I wrote to him, he updated the schematic on his site showing how he went to DC heater voltages, and I started on the 20 while the additional parts got ordered. I did get the power transformer replaced in my 45 amp, something I've been meaning to do for the past 10 years after it burned up when I was on a ship in the Persian Gulf. My Khorns have been calling me lately saying "Send us some trons". Some day I'll get around to recapping my Dynaco FM-3 also. Tex, I hope you tested the ESR on those old caps of yours.
Dave

[Arran]

Rich
I don't think that collecting and playing around with old high fidelity amplifiers classifies someone as an audiophool (A term who's use I was censored for on the other for by the way). An audiophool, to my way of thinking, is someone who buys into crackpot theories that have no basis in fact and believes that paying exorbitant amounts for snake oil type devices will genuinely lead to perfect sound A typical audiophool would be seeking to build an amplifier employing $50 paper condensers, $1000 power cables, $40 gold plated fuses, leaky black beauty condensers from old TV sets, rare and expensive triode tubes that were obsolete in 1933, etc.
Best Regards

[Arran]

Rich;
I can't see much advantage in designing an amplifier power supply to operate AC tube heaters from DC, there may be something to gain by designing recording equipment that way but in most cases proper lead dress and the use of shielded cables solves that problem inside an audio amp. The truth be told I have had more problems with my gear picking, and or radiating noise through the assorted jacks and cables tying the inputs and outputs of the equipment together then from tube filament wiring. Most of the manufactures of the amplifier that I have twisted the filament leads together and oriented then as close to the chassis as possible, in addition to using shielded cables where needed.
Best Regards
Arran

[codefox1]

I'l have to agree with all that has been said, I've built quite a few tube amps (guitar and medium-end stereo,) and generally don't use DC on the tubes, except for phono stages. There it really helps. The best way to keep hum and noise down is to use the star grounding technique, and locate the low level stuff as far as possible from the power transformer. This truly works.

I'll bet that many others have built amps from scratch and scrounged parts. Maybe we should have a contest for the ugliest working amp. I have a couple that are laughable in appearance but function very well. Something about a quad of 807's with blue flourescence bouncing around with the beat of the music is still fascinating after all these years.

[kruc]

My 45 amp is pretty ugly, and when I get my camera recognized by my laptop again I'll enter it in the contest. It's built on a 1/4" piece of powder coated scrap aluminum salvaged from a computer keyboard I got on a ship. The base still has the temporary nails I hammered in 10yrs ago to keep it straight for gluing. It does look better than the plan in Glass Audio I built it from where the author had his built into an old cardboard suitcase.
Dave

[Texasrocker]

Sounds like you guys have some very NICE homebrew tube amps indeed! A good friend previously sent me a old book published in 1957, that has 17 different amp circuit designs by Williamson. It was published by the GEC Ltd in England. The various amps-designs are from 5 thru 1100 watts each. Some good reading indeed! It also has complete parts values listed for each circuit design. The book will come in handy in the future to help me put to use my spare parts if I ever get any spare time. Ive noticed online, that the Heath W-5Ms was a overall favorite over the yrs, ( used williamson design), as well as some rare Western Electrics designs. It amazes me how expensive the new ultra-linear input & output trans are these days! Magnequest, Sowter, Jensen, and other suppliers make this hobby hard to afford financially.
Who do you guys recommend for purchase of good quality new 1% type metal-film resistors in bulk? Ive seen some bargain-bags on ebay, but the sellers dont mention the brand or where made. Most likely China or Mx would be my guess. Anyone ever tried them before?

[Arran]

Sounds like you guys have some very NICE homebrew tube amps indeed! A good friend previously sent me a old book published in 1957, that has 17 different amp circuit designs by Williamson. It was published by the GEC Ltd in England. The various amps-designs are from 5 thru 1100 watts each. Some good reading indeed! It also has complete parts values listed for each circuit design. The book will come in handy in the future to help me put to use my spare parts if I ever get any spare time. Ive noticed online, that the Heath W-5Ms was a overall favorite over the yrs, ( used williamson design), as well as some rare Western Electrics designs. It amazes me how expensive the new ultra-linear input & output trans are these days! Magnequest, Sowter, Jensen, and other suppliers make this hobby hard to afford financially.
Who do you guys recommend for purchase of good quality new 1% type metal-film resistors in bulk? Ive seen some bargain-bags on ebay, but the sellers dont mention the brand or where made. Most likely China or Mx would be my guess. Anyone ever tried them before?

If I were scratch building an amplifier I would simply order some Hammond transformers through Radio Daze or one of the other outlets, you can email Hammond for a copy of their catalog. My suspicion is that half of the boutique brand transformers were made by Hammond, or one of the biggies, in the first place and relabeled.
As for metal film resistors maybe Dale, or IRC, try a surplus outlet like Mauser. I haven't really had many problems with random bagged types as far as carbon resistors go (if that's what they are) never bought through fleabay.
Best Regards
Arran

[Doug Houston]

TEX: indeed, the Heath W5M amplifier was one of the best ones that Heath ever produced, but unfortunately, it was a Williamson. In around 1957, I bouight a new E-V Regency III speaker system, a Fisher 800 tiner, and a Heath W5M amplifier kit. Nothing could have sounded better, so I felt. After a short while, I noticed that the E-V speaker system had no highs. The tweeter was dead, so opened up the cabinet, and the tweeter was open. Back to E-V, across the state, and they replaced the cone for gratis, explaining that some amplifiers will blow tweeters. Indeed, ANY Williamson will.

Williamsons sound beautiful.I had another in the sound bay in my shop. I was working on an AM broadcast set on the bench, with a record playing thru the W'son into an ordinary speaker. Amazing, I tuned in to a station that was playing the identical record I was!! Such a cooincidence. I lifted the pickup from the record, and the station stopped playing the tune, as I did. The Williamson was a fine AM band transmitter. Didn't check, but it also must have gone up into the SW bands too. Little wonder that the Williamsons popped tewwters as quickly as you could replace them. They also oscillate at sub-sonics. I've seen a speaker with a Williamson driving it.As the music played, the cone oscillated in possibly 2 cycle high amplitude excursions.

I understand that there is some phase shift, occurring in the output transformer, and the inverse feedback loop becomes positive feedback at both high and sub-sonic frequencies. I dumped all of the Williamsons I had, and went to more conventional amplifiers. Haven't lost a tweeter since.

Williamsons are inexpensive. Tweeters aren't.

[Texasrocker]

Doug H., Many thanks for the heads-up on the Williamson design amps! Sounds like some of the Williamsons amps went into "DC spike mode" indeed! Thermal runaway you reckon? Since Im building a few amps in my spare-times allows (few), I will keep your points in mind!!
Luckily, in my recent barn-find of many vintage tube amps, Ive yielded several orig W-5M chassis ( all previously hacked) that still have the good orig power trans, chokes, & peerless branded output trans. All orig parts still test good. The hi-fiers on epay like those as well. Ive found in simply "parting the W-5M chassis' out", the "kit builders" back in 1957 didnt all know how to use a soldering-iron at all! Orig parts-o-plenty , simply bent around the orig terminal-strips under those "kit" chassis, and never soldered! No wonder so many "kits type" amps from those days had major probs. I figure those vintage heath amps-kit(s) in masses were brought into repair-shops back in the day, after orig purchasers completing the kits instructions, didnt work because of extremely "cold" solder joints! I really appreciate all the knowledge shared here indeed!!

Aaron, Many Thanks!!... for your info on the transformers & the resistors quality comparison questions!! Since I have some nice vintage Peerless orig OT's,etc, & many spare vintage chassis,all etc still test good vintage parts now onhand, I can build something good RIAA quality over the winter months. As for overall "quality" comparisons of the vintage Altec/Peerless ,UTC, Western Elec ,etc,branded I/O ( ultra-linear)transformers of yesteryear, Im sure Hammond , Jensen , & Sowter make just as good these days!! Im building a comp/limiter using sowters special-wound types ready for sale that hammond & jensen didnt offer.Havent completed that project yet. Time will tell, after a few of my RIAA Studios owners/customers verbal feedback on my new groundup-tube type special- builds for them. They have much-better ears( for RIAA) recording purposes quality than I do these days indeed! One example: ZZ Top pays " mucho extra" for "real" vintage trans installed on custom-builds vintage tube-type repros from vintage mfgrs schematics. My ears arent that good either!! Vintage peerless ultra-linear transformers "model numbers", stir up a big-fuss within the recording-industry pros! They can buy hammond, jensen, & sowters brands also. They prefer vintage "peerless" , & UTC ultra-linears types for some reason!?,I dunno either!...seems their ears can surely hear something my ears doesnt hear as well! ? Of course, at our ages, our ears are finely-tuned to yesterdays quality overall? Equal = burnt out loud-vol rockers!!!?? (hee hee) My old 300 w/Ampeg SVT amp ruined my hearing over all the yrs for sure!! Six good 6550s in PP can do that over 25 yrs!! Lordy mercy!
Once I fully deplete my stock of these vintage transformers, I will also be purchasing again from hammond, jensen, & sowter to complete my projects.

[codefox1]

Aye. Williamsons are very good if you can get the iron. Too bad you need a kid to tell the difference if you are most of us.

(edit) There still needs to be some consideration to harmonics as in all amps, and usually a small high voltage capacitor across the primary will take care of it (if it opens up, yup, tweeter toast!), along with the other common precautions such as resistors in series with, and after coupling capacitor, and resistors between screen grid and it's winding. I've seen 1K 2 watts used for this purpose a few times.

[wa2ise]

Most of the hard core tube audio guys hang out at audiokarma's tube audio forum. You name it, they know about it.