Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Value of this tube ?
Value of this tube ?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 7th February 2018, 07:22 PM   #31
Lingwendil is online now Lingwendil  United States
Now with high-fructose ASSAULT-gluten!
diyAudio Member
Lingwendil's Avatar
Join Date: Apr 2008
Location: Oakley California
Value of this tube ?
Originally Posted by audiowize View Post
Yeah, you're running up against a wall of opposition that is in response to the following progression of events that play out here and often times elsewhere on other forums:

1. Someone buys something inexpensive and poorly engineered from China.
2. They listen to it, and it's not great.
3. They change the:
A. Capacitors
B. Tubes
C. Potentiometer
D. Wire
E. Jacks/hardware
4. The piece of equipment with fatal engineering flaws is now magically perfect (proud papa syndrome).
5. Those aware of the underlying sources of the original flaws (usually an issue with poor circuit design, poor build quality, or poor transformer design) are annoyed.
Nothing wrong with buying something affordable and fooling with it until you like it, but I agree much of the improvement that one perceives can definitely be attributed to the Proud Papa syndrome. Other aspects are easy to measure and compare.

You are correct that there are some excellent inexpensive DACs available, but I wouldn't bother buying a kit (you'll need an ESD safe working surface for starters). I'd recommend starting with a Firefly or something from SMSL.

(the output impedance issue on your tube DAC could be remedied by adding feedback to the existing circuit or using the 12AU7 as a cathode follower fed from the solid state output).
There are some really nice DAC modules for some attractive prices lately. I've seen some complete dual mono modules with the PCM1794 as cheap as $40 shipped lately, and they use some decent components too. Some opamp replacement and power supply work would be all it takes to get a really nice rig for not much fuss. Good way to go for the guy that isn't necessarily interested in doing a completely scratch built design, and likes to tinker. Just pick out your USB/SPDIF to I2S of choice (I'm liking the looks of the ministreamer lately) and put it all in a nice box. Everything after that is just lashing up wire to the periphery.
Check out My 6SN7 Push-pull Flea Amplifier project! PCB COMING SOON!
  Reply With Quote
Old 8th February 2018, 01:26 AM   #32
FullRangeMan is offline FullRangeMan  Brazil
diyAudio Member
FullRangeMan's Avatar
Join Date: Aug 2009
Location: Brazil
Gentlemen await my new video on YT: How to Spot a Rare GM70 Tube.
They should cost at least $500 each graphite, copper $900 each$$$
>Never go to a psychiatrist, adopt a cat or dog from the streets. On the streets pets live only two years average.
  Reply With Quote
Old 8th February 2018, 10:43 PM   #33
Wavebourn is offline Wavebourn  United States
Designer & Technologist
diyAudio Member
Wavebourn's Avatar
Join Date: Sep 2006
Location: Pleasant Hill, CA
Value of this tube ?
Originally Posted by soulmerchant View Post
Whenever I hear "rich midrange" or "very extended lows and highs" etc. I immediately think one thing - the curcuit must be rubbish.
Is not it obvious?

This "Minimax DAC" is easy to find using a search engine:

MiniMax DAC

Looking at their quoted specs, check the output impedance values:

Output Impedance :
Tube 22K
Solid State 10K

So now I think to myself.... wow, how did they ever manage to get Solid State ouput impedance THAT high?

Maybe I should consider a career in marketing?
You already have failed your Marketing interview.
Nothing in the universe is perfect. The ideal things are the ones that are most optimal. Optimization criteria, what matters. When I hear "No Compromise Design", I want to take a sledgehammer and test how impact-proof it is.
  Reply With Quote


Value of this tube ?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tube amp reboot Re: Chinese 6P6P (6V6) Push-Pull Tube Amplifier Kit ts761100 Tubes / Valves 14 31st March 2016 10:40 PM
5687 tube-based preamp with Tung-Sol Black plates, Sylvana and Phillips ECG tube pair networld Swap Meet 3 10th August 2014 02:23 AM
FS: Yaqin CD-1 Tube Buffer w/Mullard 6DJ8 Tube. Adds tube warmth to any system. matevana Swap Meet 2 15th June 2013 01:35 PM
need diy tube preamp (line-stage) recommendation and general tube advice Musiclover4 Tubes / Valves 16 18th May 2013 04:19 PM
found tube i like, only small bits of red letter,what tube brands used red lettering? ryuji Tubes / Valves 2 16th April 2011 12:24 AM

New To Site? Need Help?

All times are GMT. The time now is 08:36 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio