Which way would You try to sell a 300B SE?

[Fabio Berutti]

Dear fellow Rodents,

I have not posted anything for a few years but it's nice to see that
ol'guys are still around. I'd need just a suggestion: I spent so
many years playing with tubes that my home is a total mess and I
need to get some of my amps OUT before I can make a new one and
carry it IN. The first one to go should be a 300B SE driven by
triode-strapped 4P1L through interstage transformers.
All tubes are Svetlana NOS and all iron comes from Hammond "classic"
series.
It is completed by its pre-amp, based on a couple of
transformer-loaded 27 (a beautiful couple of blue-glass Arcturus).
As You RATS can easily guess it is a pretty heavy and expensive
piece of audio gear, something I cannot sell so easily.
Btw, I'm not making my life out of it, I already have a job, but I
wouldn't like to give it away for less than the bare cost of the
parts...

Any suggestion?

Fabio (from Milan, Italy)

[Patrick Turner]

On Saturday, 6 October 2012 02:27:36 UTC+10, Fabio Berutti wrote:
> Dear fellow Rodents, I have not posted anything for a few years but it's nice to see that ol'guys are still around. I'd need just a suggestion: I spent so many years playing with tubes that my home is a total mess and I need to get some of my amps OUT before I can make a new one and carry it IN. The first one to go should be a 300B SE driven by triode-strapped 4P1L through interstage transformers. All tubes are Svetlana NOS and all iron comes from Hammond "classic" series. It is completed by its pre-amp, based on a couple of transformer-loaded 27 (a beautiful couple of blue-glass Arcturus). As You RATS can easily guess it is a pretty heavy and expensive piece of audio gear, something I cannot sell so easily. Btw, I'm not making my life out of it, I already have a job, but I wouldn't like to give it away for less than the bare cost of the parts... Any suggestion? Fabio (from Milan, Italy)

Before anyone would risk paying any money, how about you take several photos and also draw up a very neat copy of the schematics, and draw the F response and measured THD levels so that buyers know exactly what they are getting.
Probably nobody will buy because old men wanting to make something like the experience of making it it, if they get time, and so many just never finish what they start, and in fact old men are un-predictable to deal with and there are many gunner-dooz amoung them. But if your amps are made well enough, you'll get prices offered that are just about the worst made chinese junk because blokes who might buy are nearly all bargain hunters, and wankers who don't have "old mens's time" to fiddle around making anything, they just work and get money to pay other ppl - most often the lowest price humanly possible, often because wifey is trying to control expenditures.

Despite your descriptions, nobody really knows just what you have for sale after you have described your efforts. You might think I'm a terribly negative person after the comments I made just now but I speak from expereince of the last years since 1994 when I began working as a self employed audio tech and began making amplifiers for sale and trading in parts. NOT one single dude ever offered me a good price for anything, nearly all men have an attrocious cuntish attitude to anyone who slaves for long hours making anything. They never wanted to pay the same wage they recieved in their daily job, ie, they valued me like shit compared to how they valued themselves. Over the years approximtely 8 fellows bought transformers and chokes for projects they said they really wanted to make, and I gave them all the free advice they ever would need. Only 1man got a good working amp, and that took him 18mths, and he chose to use the worst cheapest R&C parts he could buy. 3 asked me to build their amp for them because they had no time. I refused, and said they needed to organise their time more wisely and give up crap time parked in front of a TV watching garbage, or playing games online etc.

So, good luck to anyone trying to sell their hobby results. If the hobby-homie does not have a professional look abut it, ie, good metal work knowledge well employed, it most likely won't ever sell. So don't be surprised if you have to them re-build all properly to sell and put in the hours again for virtually no reward.

But there are ppl who spend big money on audio, and maybe they have high incomes they don't have to sweat for, ie, they'd get by on 1/2 the wage OK, so if they spend on audio they don't feel their kids are starving, or that this month's rent can't be paid, or that they need new tyres for the BMW this week.

Meanwhile, be hopeful if you present your stuff forsale properly.

Out there in FOOLZ PARADIZO land, there are piles of obscenely priced audio gear not worth 2 bob.

Last month a guy brings me a pair of Jadis SET 300B amps made in 2004. They'd been blowing fuses and playing up. He'd bought them cheap at $6,000, a steal, because he said they retail new for $19,000. Well, I was asked to check them right out before he continued use with his Coral 10 Beta speakers. I find the workmanship under the chassis pretty awful, with parts hanging around in mid air because they don't believe in terminal strips or boards. The point to point wiring looks like its all been wired in China. I thought maybe the shiny brass Jadis badges with 'Made in France' are also made in China with everything else, but just where the amps are made doesn't matter these days, they all sink to the lowest common denomimator of quality.

I find there's only one heater supply for both paralleled 300B, and no individual bias adjustment possible. The single Rk was 300 ohms, much lower than it should have been for 2 tubes, but hey, didn't stupid Jadis know you must have separate R&C cathode biase networks to keep Ia similar for parallel tubes? No, they don't know this. Then I find they must have found the output power was a bit low, maybe 12Watts because B+ was a bit low with a 5U4 rectifier, so they strap Si diodes across the tube rectifer socket to lift B+, but make no change to Rk. So this possible higher PO, but only if the grid bias is able to be balanced because I found one 300B idled at 40W with the other at 12W, all over the joint, and part of the cause for fuses to blow soon after turn on with one amp.
The 6SN7 with two exactly identical cascades stages barely was able to make the drive voltage needed. The single biggest problem was both OPTs for the two monoblocs, with consecutive serial numbers.

The Jadis OPTs have NO air gap!

I got one amp biased correctly after re-building the driver amp and adding a bias balancing circuit with pot, and found I could get 17W at 1kHz, but not very clean looking. But if I adjusted F down the OPTs showed visible OPT core saturation distortion of about 5% at 250Hz. Yes, 250Hz, not 20Hz, which we might expect from a $19,000 and OPTs weighing 7Kg. The core saturates so badly below 250Hz that when I drew graph of max PO governed by a line where THD < 3%, only 1 Watt was possible at 50Hz. Jadis buyers should thus phone up Jadis to ask them for a refund of say $15,000, because most bass performance was missing!Anyway, I then measured the OPT primary L and found only 1.0 Henrys. I then turned off the amp so no DC flowed ( 150mA ) and connected an external source of Vac from a power amp and current sensing R. I measured 88 Henrys at 10Vac at 50Hz.

I am now being employed to totaly re-design and rebuild the Jadis Pile Of Shit model 300B monos. The driver amp will remain 6SN7, but have its second stage, 1/2 6SN7, fitted with anode CCS to increase Ia from the Jadis miserly 2mA to 5 mA. Input 1/2 6SN7 has 4 mA and different R&C values plus provision for 9dB GNFB. Although many SET ppl hate GNFB, in fact nobody I know hates the way I use GNFB, they all like it, because I do it right.

The Jadis OPTs have been removed. They are potted in epoxy within iron cases, and its too difficult and expensive and maybe impossible to try to remove the OPTs from the cases and put in the air gaps that Jadis forgot about, without wrecking both case and tranny. But I tested the OPTs again out of the amp using a 28V switchable dc supply and sereies R to primary, plus a cap coupled 50Hz 10Vac source from a PT, and found Lp was indeed only 1.0H with DC and 88H without DC flow, so the Jadis OPTs were in fact defective and unusable. The minimum wanted inductance with Ia flow of 150mA to get saturation Fs at say 14Hz at 10Watts means LP reactance should equal RLa of 1k5 at 14Hz so Lp must be 17 Henrys. This means the load on the tubes has become partially reactive at 14hz and XL + RLa = 1,060 ohms.

Possibly the existing OPTs could be used if the amp had been converted to parafeed, with say a plate choke of at least 20H and for 150mA and say less than 150 ohms wire resistance. Its a large choke, and must be made with 50mm T size E&I, but only 25mm stack, but with 0.45 wire wound to fill the bobbin. This can be fitted inside the narrow case across the chassis for the 2 x 5U4 which can be removed entirely. But all that is too much and then the OPT must be cap coupled, and then you have yet another C&L coupling which makes the use of only 9dB of GNFB maybe too ambitious for LF stability. But LF gain shelving probably would overcome the side effect of parafeed.

I don't have time to wind the parafeed chokes. And another thing. The Jadis amps only have 2 OP terminals but they do have 8 internal connections to allow brass straps to be adjusted to change the impedance matching for the amp. There are 4 pairs of terminals for 4 windings each equal signal voltage. So you can get 1 ohms, 4 ohms, 9 ohms and 16 ohms, but unfortunately, the loadmatching is WRONG, and to give the 300B a good batch for Ea of +400V. When connected for "4 ohms" the OPT TR = 14.9:1, so ZR = 222:1, so 4 ohms becomes 888 ohms at anode, so anode load on each 300B becomes 1,776 ohms which is TOO LOW. The Jadis is yet another POS where the maker tries to use RLa of a far too low a value.
But if one uses 8 ohms when OPT is strapped for its labelled 4 ohms then RLa for each 300B becomes 3,552 ohms which is about right for the proper Ea and Ia that should be used. So in fact Jadis have load matches for 2, 8, 18 and 32 ohms. People with 4 ohm speakers are fools if they try to use the Jadis 300B.

Possibly the Jadis POS OPTs could be used in a circlotron which can be rigged without the OPT having a CT, but all that is far too much to achieve.

I am fitting Hammond SEA 1627 meant for 2k5: 4, 8 , 16, and which have enough LP at the wanted Iadc, and I have used them before with 2 x 300B for better overall F response than anything Jadis could make. I happen to have two new tranny cases only 3 mm smaller size in which the Hammond can be potted. The powder coating I got done on the cases looks better than Jadis quality. The brass plate Jadis badges were easily removed off the old OPTs using a flat blade paint scraper. The badges can be refixed to keep the resale value up for this particular pair of amps. Maybe what I say here has upset Jadis and ppl who have bought their junk, but the only way Jadis could atone for their sins would be to have recalled all 300B models and remade them like I have, and I bet Jadis owners won't get a letter soon requesting they return their amps for total overhaul for free, and with all freight costs included.

The Huge PT Jadis use is 3 times larger than it needs to be. But luckily it has 2 x 9.4Vac windings so TWO 5Vdc can be made for the 2 300B. The 2x 5U4 are being retired with Si diodes used for the two B+ rails for 300B and 6SN7. Then I have 2 x 5Vac windings from which I get 10Vac for 6.3Vdc for 6SN7. Some resistors and others stuff can be mounted on terminal strips where 5U4 used to be. Amps will run cooler.

So, the result of so much over-priced over-hyped highend garbage on the market is that it makes Fabio's amps look like a fabulously wonderful buy. I really do congratulate Jadis and many other major makers for charging such ridiculous high prices and making such crappy quality, because at least that gives us little guys like myself and Fabio some chance rather than none at all that we might get a good sale sometimes.

My condolences to anyone who have bought Jadis 300B monobloc amps.

Patrick Turner.

[Fabio Berutti]

As usual, Patrick'a answers are.. ehm, say "exhaustive". I do know
that selling stuff is difficult, in fact I just wondered which
CHANNEL could be best: which one out of the many audio-oriented
sites? Nobody will pay 3000 bucks for a piece of audio gear without
seeing it (and maybe listening)so I suppose I should look for a
buyer within a radius of 30 km here around to be able to give him a
drive test. I'd like to post the schematics, but again, where?
Btw, my amp only uses LCR or other EU-made condensers and the 300Bs
have separate (AC) heater feeds and grid bias pots.
There was an old RCA paper stating that DHTs should be AC-heated to
provide a more uniform cathode temperature and "average" bias. In
fact with proper grounding connections they sound just a bit noisier
than when DC-fed, but much more brilliant.

I know, this will rise a hell of comments... I just think that RCA
guys were the professionals I'm not so I tend to trust them.

A nice day to all guys out there

Fabio

[Patrick Turner]

On Tuesday, 9 October 2012 00:58:53 UTC+11, Fabio Berutti wrote:
> As usual, Patrick'a answers are.. ehm, say "exhaustive". I do know that selling stuff is difficult, in fact I just wondered which CHANNEL could be best: which one out of the many audio-oriented sites?

Well, maybe ebay, because although not a strict "audio site". a lot are looking there rather than in audio sites.

Nobody will pay 3000 bucks for a piece of audio gear without seeing it (and maybe listening)

But you are incorrect. The guy here who bought the awful Jadis amps I have to re-build spent 6 grand without seeing them or listening first. And also without seeing the schematic and having someone technical appraise it first. And without knowing the mistakes the maker has made. Most people are so ignorant of so many things, yet they buy!

But they do so I suppose I should look for a buyer within a radius of 30 km here around to be able to give him a drive test. I'd like to post the schematics, but again, where?

I don't know if anyone thinks alt.binaries.schematics.electronic exists any more. Access to rec.audio.tubes and a.b.s.e seemed to collapse over 8 years ago here and I have to go through fucking Gooogle where how stuff is displayed doesn't work as easily or as well as the old days.

But you could start a website of your own, eg, www.fabioamps.com.it and then learn how to post up whatever pictures you want and say whatever you like about it. But the sales inquiries I get now are negligible.

Nobody much is interested in building anything for themselves and most audio discussion groups have guys saying one sentence at a time and they mostly seem like zombies. The price is all important, and ppl don't know how to judge if anything is good or not, and the gear for sale is overseas, so they cannot see or hear it, but they chat about it.

Btw, my amp only uses LCR or other EU-made condensers and the 300Bs have separate (AC) heater feeds and grid bias pots. There was an old RCA paper stating that DHTs should be AC-heated to provide a more uniform cathode temperature and "average" bias.

Now there is nobody who believes in the "unifirm cathode temperature" as important. Using dc on 300B and 845 heaters has become normal. I think the temp difference and emission difference due to having a different Vdc along the cathode makes a negligible difference to tube operation so dc heating is fine. Hum in amplifiers made by Jadis would not be tolerated by non technical owners who don't like having to adjust a pot to minimise hum or adjust bias, and if they do have to adjust something, they get it wrong.

In fact with proper grounding connections they sound just a bit noisier than when DC-fed, but much more brilliant. I know, this will rise a hell of comments... I just think that RCA guys were the professionals I'm not so I tend to trust them.

Well, I don't know anyone who prefers ac heating to dc heating because of better sound. I once repaired a Sun amp with PP 2A3 with AC heating and with a hum adjust pot and it sounded very ordinary, and no better than anything else.


I have an old pair of RCA amps here for a total overhaul. I'd like to trust RCA and consider them professionals, but pros are just humans, and many pros are just paid amateurs. Lets not put too many people up on pedastals where they may not fully deserve to be placed. Anyway, the tubes and much stuff RCA blokes designed was good, but the RCA amps I have to fix have an inferior schematic that could have been so much better but RCA had employed bean counters who insisted quality must be lowered to keep costs of production low to get high returns on investment. RCA had to compete with many other makers of cheaper and inferior piles of junk. Ford is a motor car maker, but hey, how come Toyota was able to sell cars to americans? How come VW could sell to americans? Real pros would have made sure former national enemies can be out performed with product quality and prices, but it seems the US car industry pros couldn't see that and pros at RCA couldn't see enough to beat competition either. How come Sony and Denon and Thorens could sell anything to america? Of course american venturists invested in Japan and Europe to get them to sell back into the US and I guess all that was driven by lust for profits rather than lust for quality. When I here that word "professional" I am often appalled because many pros don't know much except how to make a suit look good, and how to put an extra zero on the price tag, and how to rip everyone off.
Meanwhile the RCA amps are on my long list of to-dos for an old customer. I hope the old 1950s/60s iron is OK. Its hard to have to change the iron, like I am having to do with Jadis garbage made in 2004. Re-wiring the circuit is the easy part. I happen to doubt if any professionals work at Jadis. Someone said they have stopped making amps, but there is a Jadis website, and naturally enough, there are no schematics, just glossy adds for shiny looking junk.

I've always tried to buy what I thought would last me a long time so i didn't have to spend again later. So while all the houses around me have changed owners every 7 years on average, I have stayed at my joint since 1976, and I have the same furniture I made back then. Pros in the real estate business and many other related industries don't like me at all because I just won't keep buying anywhere near so much junk as everyone else. If everyone was like me there would be a terrible economic Depression for the next 20 years. Lawyers and bankers and so many "pros" would have to go and work on farms and sweep the streets, and sweat for a living. And I don't care about them either.
Patrick Turner.

[Fabio Berutti]

I'm trying Ebay, see
http://cgi.ebay.it/ws/eBayISAPI.dll?ViewItem&item=221139125917#ht_500wt_1413
and tell me if You like the appearance (I cannot post the sound)
Schematics will follow.

Happy tubed day to everybody

Fabio