Slow Blow pre?

[Bluzzi]

fotis, many thanks for postig all this. It gives us a sense of the versions.

Your Power Transformer is I supposed for 220VAC right?

I'll try and find a PT for 120VAC primary with the same or close secondaries.

jim

 

[DaxLiniere]

We are on 240v mains here in Australia, what would be the advantage of transformer isolating the B+ supply line? Just current limiting incase something went horribly wrong?

Also, would it be possible to use a toroid with 2x 110v primaries, 6v + 25v secondaries as a 240:240+12+50??

What about a 240:50 and then 50:240 (or 240:12 even?)

I suppose some of this sounds very scary, but don't worry, I'm not about to try it.

I have already disclosed my total misunderstanding of electromagnetic decoupling.

 

[toffifee]

Dax, you could use two 230:15 back to back. Look how Jakob did it in his G9 supply.
Toff
EDIT: For the second trannie you would have to use a 230:12 or 230:13 backwards if you want 250V output for the HV part...

 

[FotisGR]

My project contains 2 channels. One channel is the classic slowblow and the other is like the slowblow 2 but with 5687 at the first stage instead of 12sn7

So which one do you prefer?

There is not an easy answer , but i will try to explain it.
First if you plan to build this orgasm mashine please try to buy-use good components. I know that many people tend to build projects with cheap and sometimes bad components . I am at the other side. Every component in this project is soldered after my ears's test. I don't want to fight for this but if someone don't want to beleive me ,i will say him: just try it. Every component has its sound. So playing with the component's sound i pushed their sound character to the limits .
The classic design with the ECC82 and 5687 both srpp is something that you must hear to understand. With good tubes ( i like to use Mullard ECC82 and TUNGSOL 5687 ) ,and Jensen PIO caps , you will hear a mic pre without sound limits. Full of linearity but the orgasm is its dynamic range and bandwidth. For years i was beleiving that tubes have a small problem with the deep bass and crystal clear highs. After of this i am sure that transistors has a big problem with everything.... :grin:
The first test i made was on a broadcast studio that use Electrovoice RE20 going to Focusrite (red). The compare it remembers me when i was compare a TLM103 with a Behringer B1. The red "child" was so akward and small behind his DADDY....


The new design with 12sn7 is more velvet on the mid and more fat at the bottom. Is a perfect high class pre. It tends more to classic tube fanatics ( i am not ). It sounds more linear with a mystery velvet sound. It's bass quality is unbeleivable.

Trying to push their audio character i have to :
classic design
ECC82 by Mullard
5687 TUNGSOL
audio IN cap by Jensen PIO (1uf)
audio OUT cap By AURICAP (10uf)
cathode caps Black gate FK with Jensen PIO

For second version
Instead of 12sn7 i use a 5687 by RAYTHEON
second 5687 by PHILIPS EGC (smaller BW but perfect mid)
audio IN cap by Jensen PIO (1uf)
audio OUT cap By AURICAP (10uf)
cathode caps Black gate FK with SOLEN White caps.

What i really prefer is the classic design. When i speak to radio Jazz station the nights hours i use the classic design. Female that hear me says misc about orgasms.... :grin:
When i am at a live singing with my quitar i really prefer the second. It gives me more pounch like a small inaudible compressor...

Sorry for orgasms but is the only word that can explain its sound...

cheers
fotis

 

[FotisGR]

It would be neat to find a transformer with all three voltages needed in the PSU. I read from an old thread someone suggested the TRA200 from this company:

If you can avoid such kind of trafos to the same chassis. If you can please try with toroid trafos otherwise give to psu its own case.

 

[FotisGR]

Your Power Transformer is I supposed for 220VAC right?

Yes 230V input. My cousin has a small but high quality industry that build toroid trafos for the local market...

 

[Bluzzi]

fotis, are you saying that its better to have 1 transformer for every voltage? (one for 50v, one for 12v etc).

jim

 

[sismofyt]

heya

bluzzi; "I can't find any good links for the slowblow"

i took the stuff down from sismofyt dot net. my intentions was to make a new page, but alas i never got around. other people have uploaded some of the old schematics, i think. but there may be a few mistakes, mostly that darn reversed diode over one of the VREGs

kubi; "These are the latest and I think the best and most advanced schematics for the SB Pre"

interesting. who updated them?

bluzzi; "Also does sismofyt OK us exchanging his baby? I am saying this because I couldn't find any info on his website, so I can't presume its public now"

copyrights are for asshats

DaxLiniere; "We'd love to see your new designs if you wouldn't mind sharing them!"

what designs? the stuff on my site? no, diy

toffifee; "I´ve quickly "scanned" through those files inside the ZIP, and to me it seems that those schems are not always the newest ones"

hmm, that file is phatter than what the feds got on me

"Take into consideration: that the heater needs to be elevated (heater biasing)"

yes, it should. however, i think cathode stripping is very overrated. i've never stripped a lowpower triode yet, and i do abuse them in unspeakable manners

"that there has been a typo concerning the output tranny (Ole/Sismofyt lately told me that it would be best to use no output tranny at all)"

yeah, i think i saw lundahl 1577 (which is a great high ratio tx, btw) instead of the lundahl 1517 1:1. any proper output trannie can be used, even 1:2 or 1:4 (giving additional 6-12dB gain) if no 600R gear is being used after the pre

i've never said it's best _not_ to use an output tx. i said _i_ don't like them

"that there has been a typo in the 48V power supply drawing, if I remember correctly"

yes. reversed biased diode. stupid mistake. i did that one, i think

"perhaps shouldn´t use a relay-switched bleeder to discharge the HV caps after power-off, but better use permanent bleeders (one for each HV cap), and that the heater elevation serves as a further bleeder"

yeah, forget that relay thingy. use low resistance (50k) high wattage bleeders one for each cap

"you can use two chokes (one per channel) if you want to improve the pre further"

good idea

"change the ECC82 to 12SN7 or to another 5687 (Jazzy has done the newest version called "asymptot" with the 12SN7, Fotis has been experimenting with a "only 5687"-version)"

the 12SN7 is a double 12V 6J5 / 2C22 which is my alltime fav tube. you can't find a sweetter tone like that. ECC82 and that entire family noval shit tubes should best be avoided. i recommed the ECC82 way back then because it was / is easy to get for the group of people i designed the pre for. and that was a higher priority back then. this is 2006. we can do it better

the 12SN7 is a direct (schematic wise) drop in. much better. but not as good as the one jazzy and i cooked up. here we ditched the first SRPP stage for a straight up, hard driven classic configuration. it's just swimming in 2nd distortion and well, we like it

DaxLiniere; "it seems to be absolutely amazing and simple to build"

absolutely amazing are strong words but it's a nice biut of gear. it's simple yeah, but it's also very

DEADLY if you touch the phat caps when charged. you only get one chance in life as death is rather permanet

"I'd love to see the 3 main contributors get together and finalise a construction guide, etc. I'm not sure how I could help with that, but I'd be more than willing to give my time to make it happen"

dunno 'bout that though. i have three jobs + i'm starting a new education next month. i'm not home a lot and i'm not really into diy and / or recording anymore. i don't frequent this site and i'm a wee bit tired of that pre

so i'll need a phat bribe and / or some heavy persuasion

bluzzi; "I like "overdesign" it shows a willingness to go for the top"

it's not overdesigned. it's designed properly, that is to sound real sweet. it's not my fault all other gear is underdesigned

"lack of a final design"

there will never be a final version. you can always improve. how about using thirty car batteries, or blow your own tubes? realisticly, i'd say if you wanna do a dual SRPP the 12SN7 with a original PSU is the ticket

"Lack of definitive layout/schematic has me worried"

oh, the don't come around my place. full of crazy tube gear like an old german submarine and no schematics in site. i may be able to pull up a few old post-it notes but i'm way too lazy / busy to draw schematics. hence the lack. maybe one fo you wiz kids can draw a new one with whatever software

synthi; "Would be great have a "certified" schematic/layout"

calling wiz kid

toffifee; "For those who think about doing this pre on a PCB: the 5687 is a very hot tube, I wonder if a PCB could stand the heat"

pcbs suck. do it p2p. it's better, it's easier to fix and it'll last forever. i think it sounds better too

Bluzzi; "But do we have a definitive set of schematics?"

no, because we haven't drawn them yet

"Like I said before I have a bunch of documents. I could furnish the space on the web to have a central location for everything. How does that sound? "

i'd rather that the zip file did not get circulated around the web. it's quite confusing, contains errors etc. i'd rather that someone would be so kind to draw a new schematic and i'll host it along with describtions etc

Flundran; "It sounds great with a space on the web with all infos on the SlowBlow"

so i hear

DaxLiniere; "We are on 240v mains here in Australia, what would be the advantage of transformer isolating the B+ supply line? Just current limiting incase something went horribly wrong"

holly fukkin' ipu. don't even think about making this project if you don't know why you need that trannie

sorry to be so harsh, but i can't yell at you when you're dead

read this:

http://www.diyaudio.com/forums/showthread.php?s=01aa23b4e4d8e7b620d2489db562364a&threadid=30172

fotis, you need to quite your job and go into advertising. you could sell sand in sahara

regarding the psu, the B+ is not that critical. as long as it's somewhere between 325 and 375V all is peachy. i'd prefer mutiple trannies or one with triple secondaries. i don't like that backwards scheme. if you do it use a step down trannie with dual secondaries

anyway, fotis' trannies look nice, they're cheap(ish) and his brother needs food on the table

later,

ole frost berry

 

[sismofyt]

fotis;

"First if you plan to build this orgasm mashine please try to buy-use good components."

all these refs to orgasms is making me horny

"I know that many people tend to build projects with cheap and sometimes bad components . I am at the other side. Every component in this project is soldered after my ears's test"

that is one of the reasons i recommend using p2p. it's not easy to fit in caps of various sizes on a predetermined pcb. also it's get ruined after a fre desoldering operations. i agree with the rest as well. come jon the other side and get a free cookie

"I don't want to fight for this but if someone don't want to beleive me ,i will say him: just try it. Every component has its sound."

well, it's the sum of parts that is important. no-one plays back music from capacitors. some stuff is more important that other. the ground layout can really make or break any design. again that is easier to do real good with p2p

" So playing with the component's sound i pushed their sound character to the limits."

sure, it's like choosing the right spices when cooking

The classic design with the ECC82 and 5687 both srpp is something that you must hear to understand. With good tubes ( i like to use Mullard ECC82 and TUNGSOL 5687 ) ,and Jensen PIO caps , you will hear a mic pre without sound limits. Full of linearity but the orgasm is its dynamic range and bandwidth."

yup, that the slowblow in a nutshell. huge. natural dynamics, no cracking up on complicated signals, no compression, no noise no shite. not slow, not fast, not vintage, not phat, not warm

"For years i was beleiving that tubes have a small problem with the deep bass and crystal clear highs. After of this i am sure that transistors has a big problem with everything...."

i've been saying that hafl my life. it's much easier for me to desing something that sounds neutral with tubes. transistors are great, but not great enough. imo that is

"The first test i made was on a broadcast studio that use Electrovoice RE20 going to Focusrite (red). The compare it remembers me when i was compare a TLM103 with a Behringer B1. The red "child" was so akward and small behind his DADDY.... "

piece of shit gear. i like the silver focusrites. great bang for the buck. the compunder is miles ahead of any sub 1k euro comp. but those overpriced diecast facia NE5532 / lundahl filled hifi turds are just so bloody boring

"The new design with 12sn7 is more velvet on the mid and more fat at the bottom. Is a perfect high class pre. It tends more to classic tube fanatics ( i am not ). It sounds more linear with a mystery velvet sound. It's bass quality is unbeleivable.

i think the 12SN7 just sounds more correct to me. and any 12SN7 will do btw. you can go bonkers in really crazy expensive ECC8X tubes but they all suck. i use TFK ECC83s when i practice with my airgun

"Trying to push their audio character i have to :
classic design
ECC82 by Mullard
5687 TUNGSOL
audio IN cap by Jensen PIO (1uf)
audio OUT cap By AURICAP (10uf)
cathode caps Black gate FK with Jensen PIO"

great parts. i'd break it donw into this; oil caps or film caps. the new jensen pios are not as dirty as old russian or cornell dubilier types. sloen film caps are not as transparant as the MITs or similar. black gates rule the universe along with the ELNA starget caps. and they're not only great for cathode bypass, they can be used in the signalpath as well

For second version
Instead of 12sn7 i use a 5687 by RAYTHEON
second 5687 by PHILIPS EGC (smaller BW but perfect mid)
audio IN cap by Jensen PIO (1uf)
audio OUT cap By AURICAP (10uf)
cathode caps Black gate FK with SOLEN White caps.

i never tried a dual 5687 combo, so i've got nothing to ad

"What i really prefer is the classic design. When i speak to radio Jazz station the nights hours i use the classic design. Female that hear me says misc about orgasms....
When i am at a live singing with my quitar i really prefer the second. It gives me more pounch like a small inaudible compressor...

Sorry for orgasms but is the only word that can explain its sound...

cheers"

he. i think you're making mrs. fotis jaloux

 

[peterc]

piece of shit gear. i like the silver focusrites. great bang for the buck. the compunder is miles ahead of any sub 1k euro comp. but those overpriced diecast facia NE5532 / lundahl filled hifi turds are just so bloody boring

That is funny, I love it!

Welcome back :thumb:

Peter

 

[Svart]

copyrights are for asshats

I love it!

 

[ioaudio]

[quote author="sismofyt"]i use TFK ECC83s when i practice with my airgun
[/quote]

 

[FotisGR]

Sismofyt, Hi . I am very happy to meet you again.... :thumb:

I haven't free time this month ( i need it so much...) but i try to help everyone may wants to build this pre. Just tell me your experience with 12sn7 tubes. I have only some RCA tubes . Did you tried some of these babies?

Cheers
fotis

 

[FotisGR]

i use TFK ECC83s when i practice with my airgun

Yesterday i change my favorite mullard with a TFK ecc82. It's unbeleivable :shock:
Some friends found them on a ham festival in Germany for 7Euros each absolutely nos. ( i am radio amateur, too)
Cheers
fotis

 

[DaxLiniere]

I take it you are saying you like those tubes.
Hmmm.... discrepancies amongst members - that's a first! :grin:

 

[solder_city]

geez, just what we need. another arrogant 'designer' and a small group of flunkies hanging on his every word. i think ive seen this before. lol

 

[Kingston]

[quote author="solder_city"]geez, just what we need. another arrogant 'designer' and a small group of flunkies hanging on his every word. i think ive seen this before. lol[/quote]

calm down solder_city, it's just light-hearted pisstake for christs sakes! read between the lines.

 

[Bluzzi]

Kingston,

If you look closer Solder_City finished his line with "lol" ( laughing out loud).

He was being lighthearted. I learned to be forgiving and give the benefit of the doubt when it comes to judging internet messages. Expressing oneself by writing is not everyone's strength.


jim

 

[DaxLiniere]

Go easy on him Kingston, the lead has softened Solder City's faculties. :grin:

(No, I was NOT trying to start another pointless RoHS battle.)

 

[FotisGR]

geez, just what we need. another arrogant 'designer' and a small group of flunkies hanging on his every word. i think ive seen this before. lol

Just build it and hang up with us..... :grin:

Cheers
fotis