BLAudio LP-1 high end preamp/headphone amp

Review: BLAudio LP-1, MK II

This is a high end preamp and headphone amp. It is a two piece unit with a main unit and a separate power supply unit. I has a single pair of RCA inputs from a source and a pair of RCA outputs to an amp. It also has a 1/4 " headphone jack for use as a headphone amp. Recommended minimum headphone impedance is 100 ohms, but 300 ohms (HD650 HPs) or higher is ideal.

The main unit is 11 7/8" wide by 2 5/8" high by 6 1/2 " deep. The power supply unit is 4 3/4" wide by 2 3/4" high by 6 1/2" deep. Both units together weigh about eight pounds.

The power supply unit contains the two batteries where one is used to power the unit while the other is being recharged. The front panel of the PS unit has an on/off toggle switch, and a VU meter with a 3 way switch to select either battery or to turn off the
VU meter (to conserve power).

On the rear of the PS unit is a toggle switch to recharge either of the two batteries (where the one not being charged is used for operating the main preamp/headphone unit. The front panel of the main unit has a beautiful black acrylic plate, with a black volume control knob in the center - an unobtrusive red pinpoint light comes on when the unit is powered.

The LP-1 is a pre-amp with a headphone output. It uses a battery power buffer derived step-up transformer. This eliminates AC power grunge that degrades sound in subtle ways. The result in the BLAudio is a totally silent soundstage background against which musical images cleanly emerge.

The latest LP-1 MK II is the second edition using 2 transformers: one is
used as a cross-complementary transistor buffer driver (instead of the old push-pull MOS buffer driver), while the other transformer is the single power design with 2 batteries - you play the LP-1 with 1 battery while charging the other battery at the same time. This latest MK II version of the LP-1 offers cleaner and more dynamic sound than the original.

input impedance = 100kohm
gain = 12db
bandwidth = 3hz~150khz
thd(1khz) <= 0.05%
s/n >= 105db
power = +/-9.6V 600mAH Ni-MH battery X 2
Useage time ~ 25Hr each battery
battery life ~ 300 times recharge
recharger ~ 24V 100~300mA

I evaluate components on the following dimensions using a 5 point scale from 1 to 5, where 1 = poor, 3 = average, and 5 = excellent:

Image resolution:

A. Detail = 3
Sharp versus blurry edge to tone perimeter
B. Inner detail = 4
Separation of a tone from other tones as opposed to massing tones together in a congested whole
C. Low passage clarity = 4
Ability to reproduce quite musical passages with clarity

Image localization:

A. Fore and aft = 4
Images spaced from front to rear as opposed to collapsed close together from front to rear
B. Left to right = 4
Soundstage placement from side to side

Tone timbre:

A. Body = 3
Tone color - rich and full-bodied versus lean and washed out - sheen in first violins, glow in second violins and cellos, blare of horns, bombastic bloating of tubas, natural versus unnaturally colored tones
B. Texture =5
Feel of tone, harshness versus smoothness and hardness versus softness

Transparency = 3.5
Realness, immediacy of presence of the tones as opposed to listening through electronic veils imposed between you and the music - if it sounds like an electronic reproduction of music it lacks some transparency

Dynamic impact = 3.5
Degree of transient response in sharpness and speed of transient attacks in music

Frequency response:

Frequency extension: = 3 (some low bass roll off)
Range of response
Frequency emphasis: = 5
Peaks in response
Frequency holes: = 3 (some low bas roll off)
Dips in response

Overall this is an above average preamp that features an extremely smooth and pleasant sound - great for CD harshness and with problem components that can be shrill, or for use with non-problem components like high resolution speakers or earphones like the Etymotic 4S

I got mine to use as car headphone amp with my iRiver PCDP and Etymotic 4S earphones and it works great. I also love it as a home system pre-amp though I prefer the fuller tube tone body of my NTA preamp.

I paid $333 and got a set of C.A.R. Gold ICs included. Two day air express was $79. Contact info@cattylink.com if you are interested. For $375 I will send you mine for your audition for a week, then when you return it in the same condition I sent I will refund you $362 – you pay my shipping costs of $13 while you pay for the return shipping costs. Your payment and my refund by check only to save paypal costs.

As to the question of use as a portable, it is not good for walkman use but is great as a portable amp to use in stationary locations.

It's two rechargeable batteries are good for 50 hours of portable use, in a car, bus or airplane, or taking it to the park and listening there.

I use it in my car, with its own battery power, with the iRiver PCDP and Etymotic 4S canal phone, and it is great.

It has the SSS sound of being smooth, sweet and silky. It tames the harshness of some CDs, as well as that of the Etymotic 4S. Bass lovers will need to use bass-boost equalization though I like it with no equalization.

As for my offer for you to audition, you pay only for my shipping cost of $13 to you, plus you pay for your return shipping costs to me.

duplicate post deleted

BLAudio LP-1 MK II works great with the SA5000.

The SA5000 is clearly superior to the AKG K701 with this amp:

http://www6.head-fi.org/forums/showt...60#post1960060

Art: Yep. I think the AKG K701 sounds better to most people on most set-ups.

The fact that the SA5000 is superior to the K701 on one amp just might suggest that some people, with some amps, might like the SA5000 better than the K701.

I have been using the BLAudio LP-1 MK II with the AKG K701 connected to the headphone jack via the Etymotic 4S to 4P converter.

It is excellent. Gives a richer tone body than the SA5000 which many people would like - I still prefer the SA5000 with this amp and the K701 with my Bada PH12 though.

If you use the BLAudio with headphones of 95 ohm impedance or less, you need to use the Etymotic 4S to 4P converter for best results. If you use the Etymotic 4S you need no additional impedance - just plug it in alone.

Instead of the converter, you can get two .5 watt 75 ohm metal film resistors. Open up the BLAudio and go to the headphone jack. Cut the connected wire to the left and the right positive channels (leave the ground intact). Solder a resistor in-line to the left and then in-line to the right wires, and then solder the other end of the resistors to the left and right corresponding connections on the female headphone jack. Then you can use headphones of less than 95 ohms impedance.

Actually I get the opposite effect.

When I use the AKG K701 or SA5000 without adding 75 ohm impedance then I get some euphonic coloration and bloated and emphasized bass. When I add the 75 ohm impedance this corrects and it sounds real good - on either headphone.

Also, you do the same thing when using the Etymotic 4S instead of the Etymotic 4P - adding the impedance reduces bass and doesn't negatively change the sound at all (improves it) - same thing with adding headphone impedance to the BLAudio - sounds better when you add 75 ohms to a headphone of less than 95 ohm impedance.

Art: Actually I get the opposite effect.

When I use the AKG K701 or SA5000 without adding 75 ohm impedance then I get some euphonic coloration and bloated and emphasized bass. When I add the 75 ohm impedance this corrects and it sounds real good - on either headphone.

JaZZ: You got a strange amp that contradicts every norm.

Art: Also, you do the same thing when using the Etymotic 4S instead of the Etymotic 4P - adding the impedance reduces bass and doesn't negatively change the sound at all (improves it) - same thing with adding headphone impedance to the BLAudio - sounds better when you add 75 ohms to a headphone of less than 95 ohm impedance.

JaZZ: With just the difference that the ER-4 is designed to be used with a serial resistance (even the P has built-in 20-ohm resistors). The fact that it doesn't increase the bass has to do with its impedance curve which is different from usual dynamic headphones -- since it's not a conventional dynamic sound transducer, but uses balanced-armature drivers. Note that serial resistors change the electrical frequency response according to the impedance curve of the headphone. There's no exception to this rule.

Art: You are wrong 100% in your assertions that balanced armature drivers behave differently.

Using serial resistors in the positive leads of the amp's headphone output affects a traditional dynamic driver differently than a balanced armature dynamic driver?

Then how come both the Etymotic 4P (balanced armature drivers) and other headphones (SA5000 and K701 with traditional voilce coils) react exactly the same when a serial resistor is used to their output from the BLAudio?

All three do exactly the same when resistance is added: less bass emphasis with better bass definition and reduced bloatedness, less euphonic coloration, clearer tone imaging ahd separation of tones. These differnces are pronounced.

The same difference can also be noted when comparing the Etymotic 4P to the 4S on an amp designed to handle the 30 ohm impedance of the 4P - the 4S (with 100 ohms impedance) has less but better defined bass, and is slightly less euphonic, than the 4P (with 30 ohms impedance). This seems to be the opposite of what you say should happen.

Art: Not clear at all. Doesn't matter what the impedance curve of the ER 4P is, adding 75 ohms resistance to it to make it into a ER 4S should increase and bloat the bass according to what you say. It does not - in fact it has the opposite effect and this is is no way due to an unusual impedance curve of the ER 4P.

Now this is weird to me. Like any high end preamp, the BLAudio prefers 300 ohms or more when used with headphones. My past preamps were the same, and I got Euphonic coloration using headphones of lower than 95 ohms impedance where the lower the impedance, then the more the Euphonic bloated tone. So, it is nothing unique to the BLAudio.

Now here is a photo of the BLAudio where the control amp is on the left and the power supply (with VU meter for reading battery reserve).

The LP-1 MK2 has 2 transformers in the main control amp, 1:4 step-up and an output transformer.