EML 20B PREAMP

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happyrabbit

EML 20B PREAMP
« on: 31 Mar 2018, 11:26 pm »
Commissioned by Oliver Sayes.    Over a year in the making with a little help from FedEx  :green:

EML 20b / 10y - switchable
Coleman filament regulators
Transformer coupled outputs 
Mercury Rectifiers
Separated power supply 

See attached for more details.

the EML 20b is a beast.   

Dwight












 
« Last Edit: 1 Apr 2018, 03:52 am by happyrabbit »

FullRangeMan

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Re: EML 20B PREAMP
« Reply #1 on: 31 Mar 2018, 11:30 pm »
Wow rarely see a so powerfull supply in a preamp.
Mercury rectifiers peak tension reach many thousands volts.
Congratulations one of the best!
There is any headphone output?

A_shah

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Re: EML 20B PREAMP
« Reply #2 on: 31 Mar 2018, 11:54 pm »
Wow That is one Big Beauty ! thanks for sharing I hope those big Transformers are not a fire Hazard , Enjoy them , let us know how the pre-amp sounds ! :thumb:
Asghar

happyrabbit

Re: EML 20B PREAMP
« Reply #3 on: 3 Apr 2018, 02:06 am »
Fullrangedude,

No headphone jack.  The 20b’s are operated near 435v @ 45ma.  Health voltages for a preamp  :green:

http://www.emissionlabs.com/datasheets/EML20B.htm

a_shah,

One of the most capable preamps I have ever owned.   See attached for current setup.

Dwight




FullRangeMan

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Re: EML 20B PREAMP
« Reply #4 on: 3 Apr 2018, 02:17 am »
OK, let us know how many hours these EML tubes will lasts a long the years?

happyrabbit

Re: EML 20B PREAMP
« Reply #5 on: 16 Apr 2018, 01:13 am »
‘This tube is one of the lowest distortion tubes ever build’ -  Per EML.

This is the finest preamp tube..

Dwight


FullRangeMan

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Re: EML 20B PREAMP
« Reply #6 on: 16 Apr 2018, 01:31 am »
No prob distortion in tubes are good to ears,
the musicians call it hamonics...Do you have
seen the price from this EML20B?

« Last Edit: 16 Apr 2018, 05:56 am by FullRangeMan »

FullRangeMan

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Re: EML 20B PREAMP
« Reply #7 on: 16 Apr 2018, 06:03 am »

Man is there a train railway next to your house?

rodge827

Re: EML 20B PREAMP
« Reply #8 on: 16 Apr 2018, 11:14 am »
Sweet preamp Dwight!  :D

Do you have any specs on it?
I know specs are just what they are but a few basic ones would be good.

Input voltage?
Gain?
Output voltage?
Signal to noise ratio?
Etc...

Chris

happyrabbit

Re: EML 20B PREAMP
« Reply #9 on: 17 Apr 2018, 01:23 am »
Rodge827 - responded to your request.  Check email.  :thumb:

FRM - $600.  It’s a DHT preamp.   What can I say..cheaper than the ELROG stuff

   Great Northern Railway - aka BNSF. 

https://en.m.wikipedia.org/wiki/Great_Northern_Railway_(U.S.)

Dwight

Docere

Re: EML 20B PREAMP
« Reply #10 on: 1 May 2018, 08:55 pm »
Nice looking pre-amp Dwight - I bet it sounds very nice.

Regarding Thomas, Elrog et al, despite the universal public praise on the interwebs, they appeal to some and not others - those TT tubes and Thomas's implementation have a particular sonic aesthetic that is not to everyone's liking. I know one guy who had his 10 preamp sitting on a table unused - he appreciated it but preferred the musicality of his Shindo.

The 20B is a beast of a "preamp" tube - it can produce more output than a 2A3 or even Type 50 if you run them hard. Why is the 20B being run so close to max dissipation in a preamp?  Running at lower dissipation would greatly increase its life and the low output impedance and distortion could be maintained. The amount of voltage swing would be reduced, but that should not be an issue for a pre sitting before your power amp. It looks like the Coleman regs are used to provide filament bias on the 20B. Does Jac now warrant his EML tubes for use with Coleman regs and filament bias - he didn't a few years ago? Should be fine though if the filaments are warmed up before B+ hits the plate.

I'm probably missing some of Oliver's design objectives - he is well regarded by some and should know what he is doing by now.

All that aside, it is a really nice pre (and system!) that should sound amazing... I'd purchase another pair of tubes for back-up sooner rather than later.

Cheers.
« Last Edit: 2 May 2018, 09:06 am by Docere »

FullRangeMan

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Re: EML 20B PREAMP
« Reply #11 on: 1 May 2018, 09:19 pm »
Happyrabbit thanks for inform. Do you have think of move this real wood rack and place the equips in the floor, stm the rack is blocking the sound stage to form as the speakers are OB. Just a idea.

happyrabbit

Re: EML 20B PREAMP
« Reply #12 on: 3 May 2018, 12:29 am »
Docere -  I asked Oliver to build me a 20b preamp.  It took almost a year to achieve a functional product.  The devil is in the details  :icon_twisted:  Bespoke = No Warranty.  435V @ 43ma.   And thank you for your thoughts  :thumb:

FRM -  Artos Moonglow.  The PAP OB’s were too much for the room. 

Dwight




Docere

Re: EML 20B PREAMP
« Reply #13 on: 5 May 2018, 05:21 am »
Docere -  I asked Oliver to build me a 20b preamp.  It took almost a year to achieve a functional product.  The devil is in the details  :icon_twisted:  Bespoke = No Warranty.  435V @ 43ma.   And thank you for your thoughts  :thumb:

Dwight


No problem Dwight - it is a nice looking unit.

Not sure I follow you though. To clarify: Jac warrants his tubes even in DIY designs, if they are used per his guidelines; not sure what bespoke has to do with it. I'm not clear on the point you were making regarding taking a year to produce a functional product - can you explain?

I saw the operating point posted earlier which prompted the question about high dissipation (for a preamp). I was curious as to why those points were chosen. It is the detail I'm curious about, which is why I asked.

Being bespoke, can you share more about what you were wanted and how the design goals, design choices, and execution etc delivered that? No problem if you can't provide more detail; I've got my hands full recovering from a heavy work week and have roughly ~40kg of 2W monoblocks (not recommended!) on the bench needing about a day's worth of work to complete... enough devilish detail to sort though here, though thankfully, most of that was done at the design stage.

Enjoy.
« Last Edit: 5 May 2018, 07:40 am by Docere »

FullRangeMan

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Re: EML 20B PREAMP
« Reply #14 on: 5 May 2018, 06:37 am »
Dwight, if that huge PAP speakers are disturbing your living room or bore your wife dont be afraid from sending me them, I can made an effort to an fellow AC member and accommodate they here for a few years until you moving to a larger home.
« Last Edit: 5 May 2018, 07:53 am by FullRangeMan »