Head-Fi Amp Guide -- Submissions

Amp manufacturer: Wheatfield Audio
Amp model: HA-2
In production: yes
List price: Standard $849.00 Premium $899.00
Amplifier type: Single-ended, OTL, class A triode amplifier/ single voltage amplifier stage, single cathode follower stage/ DC- coupled input; capacitor-coupled output.
Tube complement: 1 - 6SN7GT voltage amplifier (one section used for each channel) 1 - 6AS7G cathode follower (one section used for each channel) 1 - 5U4G rectifier
Power supply: Full-wave tube rectifier/ capacitor-input filter with choke, using electrolytic polypropylene capacitors/ AC filament supply. Internal power supply.
Dimensions: 13" wide x 8.5" deep x 8" tall (including tubes)
Weight: 13 pounds
Power requirements: 120VAC 60Hz only/ 100 Watts
Fuse type: AGC-type, slow-blow, 1.5A 250V
Output Impedance 100 Ohms
Number of headphone jacks: 1
Maximum output level (1kHz, 5% THD): 620 ohm load is 13V RMS/ 36V P-P. 270 ohm load is 10.5V RMS/30V P-P.
Rated Maximum continuous output power (1kHz, 5% THD): 620 ohm load is 270mW/ 270 ohm load is 400mW.
Voltage Gain: 620 ohm load is 17dB/ 270 ohm load is 15dB
Frequency responce (+/- 3dB) 620 ohm load: 10Hz - 75kHz/ 270 ohm load: 15Hz - 75Hz
Ripple and Noise: less than 3.5mV RMS
Warranty: 6 months on tubes, 1 year on amplifier itself.
Housing material: steel, and wood.
Portable: no
crossfeed: no
RCA line inputs: one set
Other outputs: none
Possible upgrades: NOS tubes, different power cord.
Power cord detachable: yes
Picture: headphone.com
Where to buy: headphone.com

[KR...]

Cary Audio CAD-300SEI
CAD-300SEI Specifications
Weight: 51 lbs.
Dimensions: 8" H x 11" W x 14" D
Circuit Type: Single-Ended Class A
Power Output: 15 Watts
Input Sensitivity: 0.42 Volt for full output
Noise and Hum: -90 dB below full output
Frequency Response: 20 Hz to 23 KHz +/- .75 dB
Inputs: CD, AUX1, AUX2, Headphone jack
Tubes:
1 ea - 6SN7 Input
2 ea - 6SN7 Driver
2 ea - 300B Output

Power Transformer(s): 1 ea - EI Laminate, 200% Duty Cycle
Output Transformer(s): 2 ea - EI Laminate, Air Gap, 200% Duty Cycle
Resistors: 1% Metal Film
Capacitors: Oil-Filled Coupling
Power Supply Capacitors: 2 ea - 1200µF@250 VDC
AC Cord: 3 Conductor, Detachable
AC Power Requirements: 117/234 VAC @ 50/60 Hz
Consumption: 107 Watts Operation
Warm-Up Time: 3 Minutes
Break-In Time: 100 hours of playing time
Finish: Black Anodized Faceplate, Chrome Plated Stainless Steel Chassis
Standard with remote control
Retail Price: $4,500

http://www.caryaudio.comn

[ai0tron]

MELOS SHA-1






Amp manufacturer - Melos Audio
Amp name/model - Melos SHA-1
In production? NO
List price $1,195
Current "street" price $400 - $500
Type of amp - Hybrid
Stock tubes - Sovteks
Crossfeed? - NO
Other processors? - NO
Portable? - NO
Power supply - AC
Detachable power cord? Only on some later models. Post 93'??
Number of headphone jacks - 2
Jack impedance - .5 ohms
Jack output -
Jack type - 1/4" phono plug
Inputs - 3 selectable line inputs
Other outputs - Pre Amp
Speaker output rating - N/A
Possible upgrades/upgrade path - Contact melos Audio Restoration for details (www. melosaudiorestoration.com). Suggested price/performance tubes = Tesla JJ's
Housing material - Steel case with aluminum front in Black or Silver
Size (dimensions) - 19" Rack mountable
Weight

[M Rael]

Apheared 'caffeine' amp
Apheared: "It has a dual 9V battery power supply, a single quad opamp (OPA4134) configured with a gain of 16 and current-boosted outputs. The circuit board just a piece of plain protoboard, approx. 30mm x 40mm (smaller than the batteries), has 6 capacitors and the 12 resistors all standing vertically. The local power supply bypasses are probably overkill with the 100nF caps being 15mm from the supply pins. The LED power indicator is mounted on the top cover (in the penguin's belly). I was going to use a micro 1mm LED for a penguin eyeball, but it didn't look as cool or as "DIY." The power switch is a mini toggle at the back of the circuit board."


NOTE: The guy who designed and built my amp is Apheared, who is also the 'A' in CHA-47 (I'm serious.) Its not a modded 47; it was concocted as a one-off contraption all unto itself.
Heres a thread where he describes it:
http://www.headwize.com/ubb/Forum3/HTML/000801.html

and heres another article (at the bottom of the page)
http://headwize.com/projects/apheared_prj.htm

[M Rael]

Amp manufacturer: Wheatfield
Amp name/model: HA-1
In production: yes
List price: $529.00
Type of amp: Single-ended, OTL, class A triode
Stock tubes: 1x ECC82 (12AU7), 2x 7044
Crossfeed: no
Other processors: no
Portable: no
Power supply: AC
Detachable power cord: yes
Number of headphone jacks: 1
Jack impedance: 35ohm
Jack output: 600ohm @ 13V RMS, 35ohm @ 1.5V RMS
Jack type: 1/4"
Inputs: Unbalanced gold plated RCA
Other outputs: 1 pair 'pre amp' gold plated RCA
Housing material: All metal chassis with brushed aluminum faceplate. Fully vented.
Size: 9.5"x4"x7.5

[Magic77]

HeadRoom Little (Newest Version)

Manufacturer: HeadRoom Corp., www.headphone.com

Power Supply: Regulated Wall Wart(grounded) hard wired directly into amp with 6ft. cord. Power Supply made by; Elpac Power Systems.

One set of RCA inputs, One headphone jack output:1/4 inch.

Audio Image Processor switch and High Pass Filter switch on front panel.

2 green LED power indicator lights on front panel.

No ON/Off switch.

Upgrades: Can be upgraded with the Little More Power Supply, which must be done at HeadRoom Corp.

There are no specifications available for this amp; but it uses Burr-Brown OPA-604 Op-Amps. Check out www.burrbrown.com for the OPA-604 specs.

HeadRoom does not specify the type of Potentiometer used on the new Little, but I beleive it is a Clarostat Pot.

Price: $259

[shivohum]

SUGDEN HEADMASTER

Picture of amp (both a full-size image and a 70x70 pixel image)

download below (only the full-size is included)

Amp manufacturer: J.E. Sugden and Co.
Amp name/model: Sugden Headmaster
In production? (yes/no) yes
List price (final list price if no longer in production): $900
Current "street" price (used only if no longer in production): $850
Type of amp (solid state/tube/hybrid): solid state
Stock tubes (only if tubed)
Crossfeed? (yes/no, how many levels) no
Other processors? (yes/no, type, details) no
Portable? (yes/no) no
Power supply (batteries/AC) AC
Detachable power cord? (only if AC, yes/no) ??
Number of headphone jacks: 1 switched headphone socket
Jack impedance (per jack, if more than one) ??
Jack output (per jack, if more than one -- include @ #Ohms) ??
Jack type (mini, 1/4", per jack if more than one) 1/4"
Inputs (line, etc., how many) 3
Other outputs (line, pre-amp, speaker, etc., how many): Attenuated Pre Amp out Tape-out
Speaker output rating (only if speaker out -- include @ #Ohms)
Possible upgrades/upgrade path (tubes, power supply, electronics, etc.) Power cable, if it's detachable
Housing material (plastic, steel, aluminum, etc.) aluminum
Size (dimensions) 230mm x 265mm x 82mm
Weight 3.5 kg

Other Available Info:
Inputs: Three stereo pairs.
Input Impedance: 50K
Input sensitivity: 150mv in for 1volt output
Output Impedance: 4Ohms to 56kOhms
Power output: 5.5volts at onset of clipping
Bandwidth: -3dB points 10Hz & 270kHz
Frequency response: +-0.3dB 20Hz-25kHz
Signal to noise: > 90dB

[jbannow]

Amp manufacturer - Audio Technica Japan
Amp name/model - ATH-HA2002
In production? (yes/no) - Yes
List price (final list price if no longer in production) - Yen140,000 (~USD$1080)
Current "street" price (used only if no longer in production) - NA
Type of amp (solid state/tube/hybrid) - solid state (Class A)
Stock tubes (only if tubed) - NA
Crossfeed? (yes/no, how many levels) - No
Other processors? (yes/no, type, details) - No
Portable? (yes/no) - No
Power supply (batteries/AC) - AC (100V 50/60Hz)
Detachable power cord? (only if AC, yes/no) - Yes
Number of headphone jacks - 2 ( Both can be used simultaneously)
Jack impedance (per jack, if more than one) - 16 Ohms - 600 Ohms (???)
Jack output (per jack, if more than one -- include @ #Ohms) - 2400mW @ 16 Ohms; 65mW @ 600 Ohms
Jack type (mini, 1/4", per jack if more than one) - 1/4", 1/4"
Inputs (line, etc., how many) - 2 pair RCA inputs, 1 DC Direct, 1 AC Coupled (Both cannot be used simultaneously)
Other outputs (line, pre-amp, speaker, etc., how many) - None
Speaker output rating (only if speaker out -- include @ #Ohms) - None
Possible upgrades/upgrade path (tubes, power supply, electronics, etc.) - None
Housing material (plastic, steel, aluminum, etc.) - Cherry faceplate (Echizen lacquered) w/ metal body (???)
Size (dimensions) - H93 × W270 × D240mm
Weight - 5.0kg

These headphones are specifically designed to work with the ATH-W2002 headphones (though they should work with any headphones I would think). The website is http://www.audio-technica.co.jp/prod...at-ha2002.html. You can translate this with http://babelfish.altavista.com/.

[Hirsch]

Amp manufacturer: Moretto, likely a distributor for Radii Audio in China
Amp name/model: HAP-03
In production? yes
List price: sold on ebay, reserve set at $349
Type of amp: OTL tube
Stock tubes: 1 x 12AU7, 2 x 6DJ8, according to Radii audio. Tubes with the amp from Moretto were washed clean.
Crossfeed? no
Other processors? yes, an external processor is available from Radii Audio (HAP-04) which will allow use of lower impedance headphones.
Portable? no
Power supply: AC, power supply is separate from amp and attached by included umbilical cord.
Detachable power cord? yes
Number of headphone jacks: one
Jack impedance: 150 Ohms (cannot drive lower impedance headphone)
Jack output:
Jack type (mini, 1/4", per jack if more than one)
Inputs" one line imput
Other outputs: none
Possible upgrades/upgrade path: HAP-04 processor
Housing material: steel
Size: small
Weight: light

[shorton]

Single ended Class A1 - 3 watt stereo amp:
3 watts per channel integrated stereo amplifier with front panel volume control and 3 input selector switch. Single-ended class A1 no feedback DC coupled design.
Output Tubes Not Included.

Price: $1995
In production: yes

CHASSIS: Zinc plated 18 gauge cold rolled steel.
Top and bottom are 18 gauge cold rolled steel,
brass plaque logo on top plate.
The chassis is satin Iron Glimmer powder coat.
Black wrinkle powder coat on top and bottom.
Machined aluminum feet with rubber inserts.
Glass port holes are Pyrex glass with machined
aluminum rings.
OUTPUT TRANSFORMERS: Manufactured by
Electra-Print Audio Company
User selectable: 2,4,8 & 16 Ohms.
TUBES: Output optional.
One 5AR4 Rectifier Tube "Sino"
Pair 6SL7 "Sovtek"
LINE CORD: 16 gauge, 3 conductor IEC cord.
VOLUME CONTROL: Alps potentiometer.
SELECTOR SWITCH: Three input with coin silver contacts.
POWER OUTPUT: 3 watts, 5% THD @ 1kHz.
TOTAL HARMONIC DISTORTION: Less than 1%
40 - 20 kHz @ 1 watt.
POWER SUPPLY: Is a low-flux leakage design using
R.C.L.C.R.C. design.
FREQUENCY RESPONSE: (-3dB points at 1 watt)
5Hz - 32 kHz.
INPUT SENSITIVITY: 500 mV for 1 watt out
INPUT IMPEDANCE: 100 K ohms.
OUTPUT: 2,4,8 & 16 ohms. User select.
CARDAS: Speaker jacks.
Hand wired point to point for all signal circuits.
OVERALL NEGATIVE FEEDBACK: None
HUM & NOISE: .15 mV full bandwidth.
TEST MEASUREMENTS: Made with KR2A3
output tubes.
POWER REQUIREMENTS: 110 - 125 VAC 60Hz
(210 - 250 VAC 50Hz) 75 Watts
DIMENSIONS: 4" H x 14 1/4" W x 15 ½" L
WEIGHT: 40 Lbs.
HEADPHONE RECOMMENDATIONS: Sennheiser
HD600,
RECOMMENDED SPEAKER SENSITIVITY : 96 dB
or better.
WARRANTY: All components carry a 3 year parts and
labor warranty. Tubes carry the manufacturers'
warranties. Shipping and handling is not included.