In conjunction with our affiliated
partner, Jam'n Audio (US distributor for McAlister Audio), Response
Audio is now able to offer to you these exceptional tube components.
|
Stereo and Mono Bloc
Amplifiers |
MA-32 Single Ended Class A Stereo Power
Amplifier
The SE-32P utilizes a pair of horizontal output
tubes paralleled in triode mode to produce 15 watts per channel. The
input stage for each channel utilizes my proprietary constant
current/infinite plate load resistance design that combines both
triode sections of a 6N1P as the voltage amplifier and a 6CL6 as the
current source. This is a true constant current source that will
properly respond to the signal / voltage changes without a resistor
dropping large amounts of voltage, typically in standard Mu follower
circuits. This circuit design operates the input tubes at optimum
linearity and is not subject to high plate load resistance or
internal tube resistance to set the gain & linearity
characteristics. The driver stage for each channel uses a 6SN7 of
which one triode provides drive regulation and the other triode
directly drives the output tubes- no coupling capacitors are used!
The only capacitors in the signal path are between the input and
driver stage. The output stage for each channel consists of two
12DQ6 horizontal sweep tubes paralleled in triode mode operating in
class A. Without coupling capacitors each output tube receives the
identical signal and therefore both output tubes can be electrically
considered as one tube. The output transformers are custom designed
and hand wound by McAlister Audio with four primary and three
secondary interleaved sections with each layer varnished prior to
insulation. A separate well regulated bias supply with external top
chassis mounted adjustments. The power supply has over 2,000uF of
initial capacitance bypassed with film capacitors. Electrolytic
capacitors are only used in the power supply and never in the signal
path. Plate voltage is delayed 40 seconds automatically on turn on
to prevent cathode stripping. This proprietary circuit uses a damper
tube and relay circuit producing an automatic controlled delay.
Wiring is point to point with no circuit traces. A Separate power
supply chassis that contains only transformers and relays with all
rectification and regulation in the amplifier chassis. Only AC
travels through the umbilical isolating D.C. signal voltages
ensuring no possibility of interference.
Build Features:
Only film capacitors in the signal path
Hardwired point to point
Proprietary input and driver stage design directly connected to the
output tubes
Special output transformer design
Thermal delay to prevent cathode stripping
Dimensions: 19”W x 14”D
Power Supply Dimensions: 12”W x 8”D
Build Options:
240 volt configuration available on request
LED colour choices for power on and operation status
Maple, Cherry, Oak or Paduke ( similar to mahogany) wood choices
Pricing: SE-32P $2295.00
Shipping Weight: 46lbs.
MA44-SE Single Ended Class A Stereo Amplifier
Using Horizontal Output Tubes Paralleled in Triode Mode with 22
Watts per Channel
The
MA-44 stereo single ended power amplifier utilizes four horizontal
output tubes paralleled in triode mode to produce 22watts per
channel in class A. The input stage for each channel utilizes my
proprietary constant current/infinite plate load resistance design
that combines both triode sections of a 6N1P as the voltage
amplifier and a 6CL6 as the current source . This is a true constant
current source with more than enough gain to properly respond to the
small signal / voltage changes without a plate load resistor
dropping large amounts of voltage typically in cascade designs. The
driver stage uses a 6SN7of which one triode provides regulation with
the other triode directly driving the output tubes in a cathode
follower configuration without the need for capacitors. The only
capacitors in the signal path are between the input and driver
stage. The output stage for each channel consists of four 12DQ6
horizontal sweep tubes paralleled in triode mode with class A
operation. No coupling capacitors are used to drive the output tube
grids so in effect all tubes are connected together as one. This
output configuration can pass a large amount of current with
harmonic distortion in dB relative fundamental of 2nd -26, 3rd -44,
and 4th - 60. A separate and well regulated bias supply with
external top mounted chassis adjustment. The negative voltage is
adjustable and fed to the control grid of the drive tube which
determines the current flow in the output tubes. All of my power
amplifier designs use a fixed bias voltage that eliminates the
cathode resistor and electrolytic by-pass cap producing an amplifier
with fast rise time, superior dynamics and transparency. The output
transformers are custom designed and hand wound with four primary
and three secondary interleaved sections with each layer varnished
prior to insulation. The power supply has over 2,000uf of
capacitance by-passed with film capacitors- electrolytic capacitors
are only used in the power supply and never in the signal path.
Plate voltage is delayed 30 seconds to prevent cathode stripping.
This automatic system uses a damper diode providing D.C. relay
voltage through a controlled warm up. Wiring is point to point with
no circuit traces. A Separate power supply chassis that contains
only transformers and relays with all rectification and regulation
in the amplifier chassis. Only AC travels through the umbilical
isolating D.C. signal voltages ensuring no possibility of
interference .
Build Features:
Only film capacitors in the signal path
Hardwired point to point
Proprietary input and driver stage design directly connected to the
output tubes
Special output transformer design
Thermal delay to prevent cathode stripping
Dimensions: 19”W x 14”D
Power Supply Dimensions: 12”W x 8”D
Build Options:
240 volt configuration available on request
LED colour choices for power on and operation status
Maple, Cherry, Oak or Paduke ( similar to mahogany) wood choices
Pricing: MA-44SE $2695.00
MA150-8 Stereo Tube Amplifier 75Watts per Channel
The
MA150-8 stereo power amplifier utilizes 8 horizontal sweep tubes in
the output stage producing 75 watts per channel. Four output tubes
per channel lower the AC plate resistance allowing a smaller
transformer turns ratio. 12EM7/12EA7 dual triodes are used for the
input, phase splitter and driver stages with 12DQ6/6GW6 horizontal
tubes in the output stage. Bias voltage is derived from a separate
source and is well regulated with external top mounted adjustments.
Fixed bias voltage eliminates the cathode resistor and electrolytic
by-pass cap producing an amplifier with fast rise times, superior
dynamics and transparency. The output transformers are custom wound
M6 core that have 4 primary and 3 secondary sections with each layer
dipped in varnish prior to insulation. Plate voltage is delayed 30
seconds to prevent cathode stripping. This high voltage delay is
accomplished with a damper diode rectifying the relay coil voltage
through a controlled warm up. A Separate power supply chassis that
contains only transformers and relays with all rectification and
regulation in the amplifier chassis. Only AC travels through the
umbilical isolating D.C. signal voltages ensuring no possibility of
interference . The power supply has over 2,000uf of capacitance
by-passed with film capacitors. Electrolytic capacitors are only
used in the power supply and power distribution networks. Distortion
and speed are greatly improved with the addition of a drive stage
between the front end 1st gain / phase splitter and output stage.
The end result is an extremely stable high wattage power amplifier
that has a flat frequency response; low distortion and output
stage/transformer overshoot of less than 1%.
Build Features:
Only film capacitors in the signal path
Hardwired point to point
Special output transformer design
Thermal delay to prevent cathode stripping
Dimensions: 19”W x 14”D
Power Supply Dimensions: 12”W x 8”D
Build Options:
240 volt configuration available on request
LED colour choices for power on and operation status
Maple, Cherry, Oak or Paduke ( similar to mahogany) wood choices
Pricing: MA150-8 $2695.00
McAlister Audio M-170B Power Amplifier
This
amplifier has a completely novel circuit design producing 85 watts
per channel accomplished with only two horizontal sweep tubes per
channel. Hand wound output transformers with proprietary winding
configuration along with 6 interleaved primary and secondary
sections ensures superb performance with no overshoot, flat
frequency response and low D.C. resistance on the secondary due to
the low turns ratio. This provides excellent transfer and control to
the speaker load and dynamically breaks back E.M.F.
Build Features:
Only film capacitors in the signal path
Hardwired point to point
Balanced and unbalanced inputs
Special output transformer design
Thermal delay to prevent cathode stripping
Dimensions: 19”W x 14”D
Power Supply Dimensions: 12”W x 8”D
Build Options:
240 volt configuration available on request
LED colour choices for power on and operation status
Maple, Cherry, Oak or Paduke ( similar to mahogany) wood choices
Pricing: M170-B $2995.00
MB-130 mono block amplifiers
The
MB-130 mono block amplifiers share the same circuitry as my MA150-8
amplifier but are dual mono with 6 output tubes per channel. 12EM7
dual triodes are used for the input, phase slitter and driver stages
and EL504/PL504 horizontal tubes for the output stage. Bias voltage
is derived from a separate source and is well regulated with
external top mounted adjustments. Fixed bias voltage eliminates the
cathode resistor and electrolytic by-pass cap producing an amplifier
with fast rise times, superior dynamics and transparency. The output
transformers are custom wound M6 core that have 4 primary and 3
secondary sections with each layer dipped in varnish prior to
insulation. Plate voltage is delayed 30 seconds to prevent cathode
stripping. This high voltage delay is accomplished with a damper
diode rectifying the relay coil voltage through a controlled warm
up. A Separate power supply chassis that contains only transformers
and relays with all rectification and regulation in the amplifier
chassis. Only AC travels through the umbilical isolating D.C. signal
voltages ensuring no possibility of interference. The power supply
has over 2,000uf of capacitance by-passed with film capacitors.
Electrolytic capacitors are only used in the power supply and power
distribution networks. Distortion and speed are greatly improved
with the addition of a drive stage between the front end 1st gain /
phase splitter and output stage. The end result is an extremely
stable high wattage power amplifier that has a flat frequency
response; low distortion and output stage/transformer overshoot of
less than 1%.
Build Features:
Only film capacitors in the signal path
Hardwired point to point
Special output transformer design
Thermal delay to prevent cathode stripping
Dimensions: Each mono block; 12”W x 19”D
Power Supply Dimensions: two power supplies; 12”W x 8”D
Build Options:
240 volt configuration available on request
LED colour choices for power on and operation status
Maple, Cherry, Oak or Paduke ( similar to mahogany) wood choices
Pricing: MB-130 $4495.00
OTL-195 Mono Block Amplifiers 195 watts per channel
An
innovative new design offering superb efficiency and reliability
with a continuous output of 195 watts per channel using 16 sweep
tubes per mono block in the output stage.
OTL’s ( no output transformer ) have the potential to produce
lots of power with clean effortless sound and most important, very
musical but also have a number of problems that have to be over
come;
- Inability to drive low impedance loads.
- Numerous adjustments to keep internal signal balance.
- Shortened output tube life
- D.C. offset voltage; in fact some manufactures use large
capacitance in series with the output tubes and speaker load to
eliminate D.C. Any time large electrolytic capacitance is used
in the signal path performance suffers.
- Reliability
With this in mind I designed an OTL that overcomes all these
issues- the original prototype designed 10 years ago is used in my
personal home as the main amplification and still has the original
output tubes.
Completely balanced from input to output with only three user
adjustments required and internal balance that is not dependent on
tube emissions. The ability to properly drive 4 ohm load impedances.
No electrolytics in the signal path and horizontal sweep tubes in
the output stage that have lower second and 4 th harmonics, pass
lots of current and are extremely reliable compared to the standard
array of audio tubes. A very unique circuit that tracks the signal
level in the driver stage and modulates the control grids of the
output tubes. This gives superb efficiency as a super cathode
follower and at low to moderate signal levels the output tubes are
only operating at 1/3 of their plate dissipation. In addition the
idle switch on the front panel reduces the operating current in the
output stage to a fraction of the sum- a great standby feature. The
OTL-195 using no output transformers with superb reliability, low
output impedance, directly coupled is the best amplifier that I have
designed and is distinguished from all other amplifier designs with
a magical musical sound.
Build Features:
- Only film capacitors in the signal path
- Hardwired point to point
- Proprietary input and driver stage design directly connected
to the output
- 195 watts per channel
- Balanced outputs
- Balanced and unbalanced inputs
- Simple bias check / adjustment
- Frequency response 0.2dB 10Hz to 80kHz
- THD 0.08% @ 5 Watt
0.3% @50 Watt
0.31% @150 Watt
0.36% @ 195 Watt
- Output impedance 0.5 ohm
- Unbalanced input 1.7 Vrms for full output
- Balanced input 2x 0.85 Vrms for full output
- Thermal delay to prevent cathode stripping
- Simple bias check / adjustment
- Separate Dual Mono power supply14”W x 12”D
- Mono blocks finished in hand rubbed curly Maple
- Dimensions:16”W x26”D 35LBS each
Build Options:
- 240 volt configuration available on request
- LED colour choices for power on and operation status
- Maple, Cherry, Oak or Paduke ( similar to mahogany) wood
choices
Pricing: OTL 195 $8895.00
MA-150 Special with polished aluminum and copper sub
chassis with Separate Power Supply Chassis
Here
is a very unique MA-150 available as a special order. Polished top
and bottom plates with a copper sub chassis. 12EM7/12EA7 dual
triodes are used for the input, phase slitter and driver stages and
PL-509 horizontal tubes for the output stage. Bias voltage is
derived from a separate source and is well regulated with external
top mounted adjustments. All of my power amplifier designs use a
fixed bias voltage that eliminates the cathode resistor and
electrolytic by-pass cap producing an amplifier with fast rise
times, superior dynamics and transparency. The 12EA7/12EM7 dual
triode has one section similar to the 6SN7 but with a 10 watt plate
dissipation and the other similar to the ECC83. In each channel the
two 12EA7/12EM7 sections do the first stage gain and phase splitting
while the second 10 watt sections accomplish the drive for each
output tube. This unit comes with a front mounted volume control and
rear mounted on/off switch.
The output transformers are custom wound M6 core that have 4 primary
and 3 secondary sections with each layer dipped in varnish prior to
insulation. Plate voltage is delayed 30 seconds to prevent cathode
stripping. This high voltage delay is accomplished with a damper
diode rectifying the relay coil voltage through a controlled warm
up. The separate power supply uses a massive power transformer
system. High speed diodes, regulation and 2x 15,000uf of capacitance
paralleled with film capacitors are used in the power supply.
Electrolytic capacitors are only used in the power supply and power
distribution networks. Distortion and speed are greatly improved
with the addition of a drive stage between the front end 1st gain /
phase splitter and output stage. The end result is an extremely
stable high wattage power amplifier that has a flat frequency
response; low distortion and output stage/transformer overshoot of
less than 1%. This amplifier comes complete with a detachable power
cord, IEC input, ceramic tube sockets, NOS tubes, and instruction
manual with bias instructions. Tube compliment 4x 12EA7 / 12EM7, 4x
Pl-509 and a 6AX4 used as the thermal delay. This unit comes with a
one year warranty parts and labour except the tubes that are covered
for 90 days.
Build
Features:
Point to Point wiring
No electrolytic capacitors in the signal path
High quality film capacitors used in the signal path
Regulated fixed bias
Separate regulated screen supply
Amplifier dimensions:17”W x 14”D Power supply 8”H x 14”W X 8”D
Build Options:
Front panel lettering
LED color choice for power on and operation status
240 volt configuration available on request
Umbilical cord length between the power supply and amplifier to suit
your needs.
Pricing: PP150-8 $2995.00
Shipping weight: a) amplifier 40lbs b) power
supply 25lbs
|
Stereo Preamplifiers,
Headphone and Phono Amplifiers |
MA-10B Custom Triode Line/Headphone Amp
Here
is a custom built line level pre-amp & headphone amplifier. This
amplifier is a special proprietary designed mu-follower with a 6B10
(both sides paralleled for the lowest noise and output impedance) as
the gain tube and a 6SN7 as the current source for each channel.
This is an extremely stable natural sounding pre-amp that uses no
feedback and has no electrolytic capacitors in the signal path- only
in the power supply.
The high voltage power supply regulator circuit uses a horizontal
sweep tube followed with an oil filled capacitor. Secondary
filtration with electrolytics by-passed with film caps. Regulated
D.C. filament supplies are used for the6B10’s and 6SN7’s. The front
panel has a four position selector switch, mute switch, volume,
balance and headphone jack. The back panel has two sets of line out
(RCA) four sets of RCA inputs, IEC connector and fuse holder. Using
as a headphone amplifier there is plenty of headroom with 92 volts
peak to peak that will sufficiently drive any headphone from 10 –
2,000 ohm impedance. As a line pre-amp you have 17dB of gain without
feedback.
To sum up, this preamp uses no feedback, no transistors; no
electrolytic capacitors in the signal path, horizontal sweep tube
and choke loaded rectification with D.C. filament supplies. This
unit can serve as a high end purity line stage and also a superb
headphone amplifier.
Build Features:
- No feedback design
- Hardwired point to point.
- Only film capacitors in the in signal path- no electrolytic
- Choke loaded power supply
- D.C. filament supply
- 17db gain
- 100k input impedance
- LED color choice for power on and operation status
- Maple, Cherry, Oak or Paduke ( similar to mahogany) wood
choices
- Amplifier dimensions:19x W x 14”D
Options:
- Headphone / line front panel selector switch
- Additional inputs / outputs
- 240 volt configuration available on request
MA-15 Line Stage Pre-Amplifier with MM Phono Stage
The
MA-15 shares the identical circuit as the MA-10B line amplifier with
the addition of a 4-tube M/M phono stage. This amplifier is a
special proprietary designed mu-follower with a 6B10 (both sides
paralleled for the lowest noise and output impedance) as the gain
tube and a 6SN7 as the current source for each channel. This is an
extremely stable natural sounding pre-amp that uses no feedback and
has no electrolytic capacitors in the signal path- only in the power
supply. The phono stage uses 2x 6922or 6N1P and two 12AT7 tubes in a
special proprietary phono stage with separate regulated high voltage
and D.C. filament supplies. RIAA equalization is passive with no
feedback
The high voltage power supply regulator circuit uses a horizontal
sweep tube followed with an oil filled capacitor. Secondary
filtration with electrolytics by-passed with film caps. Regulated
D.C. filament supplies are used for the 6B10’s and 6SN7’s. The front
panel has a five position selector switch, mute switch, volume,
balance and headphone jack. The back panel has two sets of line out
(RCA) five sets of RCA inputs, IEC connector and fuse holder. Using
as a headphone amplifier there is plenty of headroom with 92 volts
peak to peak that will sufficiently drive any headphone from 10 –
2,000 ohm impedance. As a line pre-amp you have 17dB of gain without
feedback and 30db of gain in the phono stage
To sum up, this preamp uses no feedback, no transistors; no
electrolytic capacitors in the signal path, horizontal sweep tube
and choke loaded rectification with D.C. filament supplies.
Build Features:
- No feedback design
- Hardwired point to point.
- Only film capacitors in the in signal path- no electrolytic
- Choke loaded power supply
- D.C. filament supply
- 17db gain – Line Stage
- 30dB gain with passive RIAA equalization in the phono stage
- 100k input impedance
- LED color choice for power on and operation status
- Maple, Cherry, Oak or Paduke ( similar to mahogany) wood
choices
- Amplifier dimensions:19x W x 14”D
Options:
- Headphone / line front panel selector switch
- Additional inputs / outputs
- 240 volt configuration available on request
Pricing: MA-15 $1995.00
Shipping weight: 24lbs
PH-6 Moving Magnet / Moving Coil Phono Stage
The
PH-6 has both M/M & M/C inputs with a separate power supply. Front
panel input selectors for both the moving coil and moving magnet
inputs. The moving coil load selector range 20/50/150/250/500/1000
and moving magnet 47/100/500/1K/10K/47k. The separate power supply
supplies two well regulated high voltages to both M/M & M/C stage
along with regulated D.C. filament supplies. Tube compliment 2x
6922or 6N1P and two 12AT7 tubes RIAA equalization is passive with no
feedback with 30dB MM and 30dB MC gain.
Build Features:
- No feedback design
- Hardwired point to point.
- Only film capacitors in the in signal path- no electrolytic
- Choke loaded power supply
- D.C. filament supply
- MC 30db gain
- MM 30dB gain with passive RIAA equalization
- LED color choice for power on and operation status
- Maple, Cherry, Oak or Paduke ( similar to mahogany) wood
choices
- Amplifier dimensions: 12” W x 8”D
- Power Supply dimensions 12”W x 8”D
Options:
240 volt Mains
LED colour choice
Pricing: PH-6 $1195.00
EA-8 Electrostatic Headphone Amplifier
Here
is the ultimate expression in electrostatic tube headphone
amplification. The EA-8 replaces both the EA1 & EA-4 now using 4
12DQ6 horizontal sweep tubes configured in triode mode for the
output. The inputs from your source are routed through volume /
balance controls and into the first dual triode paralleled
amplification stage followed by four 6CG7 dual triodes. The power
supply uses high speed fast recovery diodes with choke loaded HV
rails utilizing two horizontal sweep tubes for the regulated high
voltage supplies. All D.C. filament supplies. Only HQ film caps are
used in the signal path. The front panel has two Stax outputs, one
for high bias and one for low bias that will work with virtually all
Stax products – high bias, low bias and electret. If desired
Sennheisser and Koss outputs can be added at no additional charge
but the customer will have to supply the appropriate panel jacks.
Tube compliment is 2 x 12AU7, 4x 6CG7, 6x12DQ6.
Build Features:
- Only film capacitors in the signal path- no electrolytic
capacitors (only in power supply circuits).
- Choke loaded and regulated high voltage circuits.
- Hardwired point to point.
- Dimensions 19”W x 14”D
Build Options:
- Customer options of additional output jacks- to be supplied
by customer
- Front panel choice of white or gold lettering on black
- LED color choice for power on and operation status.
- XLR input connectors.
- Solid side panels in Maple, Cherry, Oak or Paduke ( similar
to mahogany )
- 240 volt configuration available on request
Pricing: EA-1 $1895.00
Shipping Weight: 28lbs
