# BHK Preamp burn in time
**URL:** https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699
**Category:** Preamplifiers
**Created:** [April 20, 2022, 5:27pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699 "2022-04-20T17:27:11Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@gd7288](https://forum.psaudio.com/u/gd7288)
#### Post date: [April 20, 2022, 5:27pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/1 "2022-04-20T17:27:11Z")
Mine hopefully arrives friday.
Is there a consensus re: how much time it needs to burn in?
Or does it need time?
Thank you
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### Author:  [@jamesh](https://forum.psaudio.com/u/jamesh)
#### Post date: [April 20, 2022, 6:12pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/2 "2022-04-20T18:12:25Z")
Man, my BHK 250 sounded outstanding out of the box. I got a lot of gear at the same time so it’s hard to say how long the amp itself took to break in. The most common number I hear for the 250 is about 250 hours.
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### Author:  [@gd7288](https://forum.psaudio.com/u/gd7288)
#### Post date: [April 20, 2022, 6:27pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/3 "2022-04-20T18:27:53Z")
Apologies…meant BHK preamp
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### Author:  [@stonefree1911](https://forum.psaudio.com/u/stonefree1911)
#### Post date: [April 20, 2022, 6:37pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/4 "2022-04-20T18:37:13Z")
250 hrs of burn in? Yowsa… Just ordered a Parasound A21+, wasn’t planning on anywhere near that. Of course…I’m also going to just plug it in and go…
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### Author:  [@Palouse](https://forum.psaudio.com/u/Palouse)
#### Post date: [April 20, 2022, 6:39pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/5 "2022-04-20T18:39:02Z")
> [@stonefree1911](#):
>
> I’m also going to just plug it in and go…
That’s what I did with all my PSA stuff—have my cake and eat it too!
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### Author:  [@davida](https://forum.psaudio.com/u/davida)
#### Post date: [April 20, 2022, 6:53pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/6 "2022-04-20T18:53:19Z")
> [@stonefree1911](#):
>
> 250 hrs of burn in? Yowsa… Just ordered a Parasound A21+, wasn’t planning on anywhere near that. Of course…I’m also going to just plug it in and go…
No where near anything like that…A21+ will sound wonderful
right out of the box…
On initial start up…give it idle time to form up power supply
caps etc that may need a little settling time giving the biasing
time to form up as this is the initial 1st use…
Both my my former A21 and current JC5 were amazing right
out of the box!! Of course as run time accumulated the better
they sounded…
When you do set it up 1st time be sure to check 2 switches on
the back on is for balanced/unbalanced mode be sure it is in
the mode you will use.(XLR/RCA) the other is the stereo/bridged
switch…check to be sure it is in the stereo mode. Next check
the gain pots ( I leave mine on max ) to be sure they are both
at the same levels…
You will be good to go and enjoying your new A21+ speedily!!!
Wish you the best
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### Author:  [@sixpack1](https://forum.psaudio.com/u/sixpack1)
#### Post date: [April 20, 2022, 6:59pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/7 "2022-04-20T18:59:16Z")
My BHK 250 sounded great out of the box too. Yes it does get better with time though!
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### Author:  [@jamesh](https://forum.psaudio.com/u/jamesh)
#### Post date: [April 20, 2022, 7:14pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/8 "2022-04-20T19:14:19Z")
Oh no problem. Not sure why I assumed BHK250 either. The preamp seems to be just a little more. Seems folks still enjoy this puppy out of the box, but I hear numbers like 300 and 350 being thrown out more commonly.
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### Author:  [@vkennedy61](https://forum.psaudio.com/u/vkennedy61)
#### Post date: [April 20, 2022, 7:19pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/9 "2022-04-20T19:19:52Z")
Since it’s a Pre, you can run music through it with your rig turned down really low or with the amps off during quiet time. Non-stop that’s really just 10 days.
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### Author:  [@gd7288](https://forum.psaudio.com/u/gd7288)
#### Post date: [April 20, 2022, 7:38pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/10 "2022-04-20T19:38:11Z")
Vincent
Hilarious
That was going 2b my next question
Tom clark here
We have talked on The Roon boards recently
Thanks
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### Author:  [@gd7288](https://forum.psaudio.com/u/gd7288)
#### Post date: [April 20, 2022, 7:39pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/11 "2022-04-20T19:39:17Z")
Just came off 17 days burn time with my m1200’s
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### Author:  [@vkennedy61](https://forum.psaudio.com/u/vkennedy61)
#### Post date: [April 20, 2022, 8:14pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/12 "2022-04-20T20:14:48Z")
> [@gd7288](#):
>
> We have talked on The [Roon](https://roonlabs.com/) boards recently
Hi Tom! It’s a small internet after all. 😄
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### Author:  [@vkennedy61](https://forum.psaudio.com/u/vkennedy61)
#### Post date: [April 20, 2022, 8:15pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/13 "2022-04-20T20:15:50Z")
> [@gd7288](#):
>
> Just came off 17 days burn time with my m1200’s
What’s your impression? Are you happy? I hope so.
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### Author:  [@eral63](https://forum.psaudio.com/u/eral63)
#### Post date: [April 20, 2022, 8:23pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/14 "2022-04-20T20:23:55Z")
Out of the box my BHK pre sounded very tight and a little edgy. I called the dealer and was seriously worried…but after some days it suddenly opend up with a smooth sound and a big soundstage😄i have now approx 200 tube hours and it’s still improving…
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### Author:  [@chuck929](https://forum.psaudio.com/u/chuck929)
#### Post date: [April 20, 2022, 8:41pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/15 "2022-04-20T20:41:09Z")
Just hook it up and start listening already! It only gets better.
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### Author:  [@gd7288](https://forum.psaudio.com/u/gd7288)
#### Post date: [April 20, 2022, 10:46pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/16 "2022-04-20T22:46:00Z")
Love them
They are fantastic
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### Author:  [@Gary\_M](https://forum.psaudio.com/u/Gary_M)
#### Post date: [April 21, 2022, 4:54am UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/17 "2022-04-21T04:54:55Z")
It took around 600 hrs before I thought my BHK preamp settled in and really started to sound amazing. Before 600 hrs it was a bit of a rollercoaster ride. Here are the notes I took during the break-in process.
First impression, not as good as running DSD directly to the amp. Next morning things sounded a lot better, but seemed to regress later in the day. A little apprehensive about purchase, but was also feeling the same way about my other PSA purchases before they were fully broken in.
Been a rollercoaster ride the whole way. Sounded amazing at around 300 hrs, then became dull with bloated bass between 500 and 580 hrs. Back to sounding amazing at around 600 hrs.
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### Author:  [@owlsalum](https://forum.psaudio.com/u/owlsalum)
#### Post date: [April 21, 2022, 5:51am UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/18 "2022-04-21T05:51:57Z")
For whatever reason, my BHK pre was well sorted fresh out of the carton. Very little change with accumulated powered time and it sang nicely from day one. I will share a related observation for what it is worth. I didn’t care for the stock Psvane 12AU7s. Sounded threadbare in my system and burn in didn’t change that impression one iota. After 100-200 hours I had heard enough. I dispensed with them in favor of a pair of NOS Telefunken 6922s I had in my tube box and never looked back. The upshot: take maximum advantage of the flexibility your pre offers in tube type and bias. I did and was stunned by what I could elicit from my pre even with low hours of use.
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### Author:  [@RonP](https://forum.psaudio.com/u/RonP)
#### Post date: [April 21, 2022, 2:25pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/19 "2022-04-21T14:25:57Z")
I had the same experience as @owlsalum. My BHK pre sounded great right out of the box; even better after about 48 hours.
And I went thru a lot of 12V tubes and never found any that I liked nearly as much as NOS 6V Telefunkens. After a couple years, those 6DJ8 are still quiet and glorious sounding.
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### Author:  [@gd7288](https://forum.psaudio.com/u/gd7288)
#### Post date: [April 21, 2022, 7:10pm UTC](https://forum.psaudio.com/t/bhk-preamp-burn-in-time/28699/20 "2022-04-21T19:10:09Z")
Thanks to all for your answers.
Gonna give it 300 hours
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