Vintage HiFi Audio Forum

Audio Discussion => DIY => Topic started by: Vpgh on August 10, 2019, 05:14:27 PM

Title: Preamp design point
Post by: Vpgh on August 10, 2019, 05:14:27 PM
Hello everyone,
I completed my tube remote controlled DIY preamp with phono-in project recently and looking for input for it's design/appearance. The original idea was old fashionable looking silver-face device with round volume knob. I'm not professional designer or artist, however, please find attachment.

I put random wooden pieces on the sides of preamp just for picture. 
What seems better: with wooden sides or without?

Thanks
Title: Re: Preamp design point
Post by: schwarcw on August 10, 2019, 06:59:28 PM
Very nice job Vince!  I like the wood.  I also would like to hear this preamp sometime!
Title: Re: Preamp design point
Post by: scorpio333 on August 10, 2019, 08:41:14 PM
Very nice! I'd go with wood sides, but even without it's a very simple, clean look.

Interesting seeing/reading more info on the internals.
Title: Re: Preamp design point
Post by: Sir Thrift-a-Lot on August 10, 2019, 09:36:17 PM
With for sure.
Title: Re: Preamp design point
Post by: MacGeek on August 11, 2019, 06:46:44 AM
Agree with the group about the wood.  Is that a Mac 5100 integrated underneath?
Title: Re: Preamp design point
Post by: Jim Pittsburgh on August 11, 2019, 07:17:33 AM
wow   very nice job! would love to hear it some time! 
Title: Re: Preamp design point
Post by: Kingman on August 11, 2019, 08:03:54 AM
Nice job! It looks great either way but I like the wood trim.
Title: Re: Preamp design point
Post by: Vpgh on August 11, 2019, 03:31:09 PM
Agree with the group about the wood.  Is that a Mac 5100 integrated underneath?
MA 230 - McIntosh 1st transistor-tube hybrid.
Title: Re: Preamp design point
Post by: Vpgh on August 11, 2019, 03:32:25 PM
Thanks everyone for suggestion. I'll be in friend garage in next couple weeks  :)
Title: Re: Preamp design point
Post by: Vpgh on August 11, 2019, 03:49:28 PM
Very nice! I'd go with wood sides, but even without it's a very simple, clean look.

Interesting seeing/reading more info on the internals.
Let try!
I relative novice in vinyl spinning - in my ex-country was impossible to buy any records in brick-n-mortar stories or online. However, I had have an opportunity to spend a week or two every year abroad, but crazy custom law ...
I was driven by idea to have a modern (eq. with remote stick - I'm pretty lazy person ;) tube preamplifier with phono section. I've learned a lot on the service-manuals for Big Names preamps and DIY discussion boards across the World.
Concept is the shortest signal path with no-boutique tubes: unfortunately, the price of NOS tubes literally jumps rapidly last couple years. 
Title: Re: Preamp design point
Post by: Vpgh on August 11, 2019, 04:06:46 PM
I had tried some phono-stages schematic and finally choose 2 stage solution based on EF86 +6DJ8 tubes. It's not very popular in mass production, however, I found that I like my vintage Scott tube receiver music reproduction - expressive, dynamic. I designed my own PCB for both stages of preamp , ordered those from Chinese FAB (cost saving- 5 times difference with US based FAB!). Toroidal power transformer to minimize magnetic leakage made in NJ, custom solid aluminum  faceplate made in California. Most of the parts were ordered from Mouser Electronics (Texas)  except tubes. 
I had tried to save on new Russian Tung-Sol re-issue with absolutely inacceptable result: sound was noisy and flat. I spent coupe more bucks for high -quality Dale resistors and silver-Mica capacitors in RIAA correction circuit, bought NOS 6267 GE tubes for the 1st stage - now I satisfied with music reproduction.

One of the forum members listening my preamp for couple days in his system and had notes better soundstage .vs. his TOTL vintage solid-state preamp .
Title: Re: Preamp design point
Post by: Vpgh on August 11, 2019, 04:11:53 PM
What I like: deep, multi-layers, perfectly defined soundstage with natural voices and real size of music instruments.
What I don't: the level from CD and phono is not the same, remote control is cheap plastic. Wife personally hates bright green LEDs on front panel. I need a kind of fundraising for new indication PCB  ;)

What's the plan: wooden trim on the sides, new remote control (fine wood, like on Italian audio stuff?), order updated indication PCB.

Any suggestions?