Estremo 88
by Response Audio
Estremo  (extreme) (to the extreme)

No Compromise Single Ended KT88 Stereo Amplifier

The "Estremo 88" is a single ended dual chassis power amplifier designed around the 6550/KT88 tube types. The Estremo 88 amplifier yields about 15 watts in pure Class A, single-ended operation. It uses a single KT88 output tube per channel.

After several years in development, The Estremo 88 amplifier is ready to serve you with 15 watts of pure Class A single ended bliss. This is accomplished by using natural materials for the chassis, top rated components and proper design techniques throughout. After several years of 'listening' to different mediums, we have found our chassis and design concepts allow the Estremo 88 to produce a presentation that is like live music rather than a synthetic hi-fi sound.

The heart of any decent tube component is the power supply. The power supply, located in a separate chassis, is choke regulated using a single 5U4 tube for the rectifier. One of the features that make the Estremo 88 so special is it's large  polypropylene power supply. There are no electrolytic capacitors found in the power supply of the Estremo 88.

The 45+ pound power supply with it's 16 pieces of very large polypropylene capacitors had to be designed and built into its own dedicated chassis. The power supply chassis is lined with a copper foil to further prevent any interference. This not only allows proper room and layout of the power supply but also prevents interference with the analog circuit providing a dead quiet, black background.

The Circuit:

The Estremo 88 uses a single 6SN7GT dual triode in the input stage operating in an unusually high current mode, the gain control optional volume potentiometer is placed after the first gain stage to allow the amplifier to be driven by any source with a minimum of noise introduced by this first stage. The 6SN7GT input stage feeds two 12AX7s used in the driver stage.

Feature Overview:

• Twin chassis design with external power supply

• Copper lined power supply chassis

• Star grounding technique used throughout

• The analog and power supply circuits are 100% P-T-P (point-to-point) wired.

• High purity OCC solid silver signal path wiring

• Coupling capacitors are the highly regarded Mundorf Silver/Oil (others available upon request) providing a seductive and emotional presentation that will have you calling in sick to work.

• Teflon bypass on output tube cathodes

• Film bypass on driver tube cathodes

• A fused output cathode provides extended protection

• Silver RCA input connectors

• Silver XLR input connectors

• Cryogenic treated silver fuse holder

• Cryogenic treated silver IEC connector

• WBT speaker binding post

• Estimated weight: 85 lbs.

• Hand built in New York USA

The Chassis:

The chassis of the Estremo 88 is constructed of 1-1/2" thick Baltic Birch ply at the front and sides and 1/2" top with the circuitry built on heavy gauge aluminum. The rear panel of both chassis is constructed of 1/4" acrylic. Satin black or real wood veneer options are available.

The Estremo 88 ships in two separate crates with an estimated total weight of 95-100 lbs.

The Estremo 88 is a complex product to build. Every aspect of this amplifier is hand built. Expect estimated turnaround times of  8-12 weeks.

For a more affordable, single chassis version of the Estremo 88, be sure to check out the Bella 88 single chassis design.

Auditions: A Bella 88 finished in high grade Japanese Tamo Ash real wood veneer and sporting the TAP remote volume will soon be on display and available for audition at Response Audio.

Prices	Plus shipping from Response Audio, Endicott, New York 13760, USA
Estremo 88	Price $10,699 Direct Sales Introductory Price: $8,199
Options and Upgrades
Balanced Inputs	+$250 Adds balanced input transformers while still maintaining the ability to switch between balanced and single ended
Upgrade the Line Stage Capacitors	+$300 Substitute VH Audio V-Cap TFTF capacitors in the coupling stage.
Volume Control	+125 Allows the single input signal to go through a custom stepped attenuator using Dale RN 1% resistors. Consider if using only a single source. Can still be used with a preamp as well.
Remote Volume	+479 Allows the single input signal to go through a custom TAP remote system by Bent Audio. The PRM-1 level control readout is located on the front panel of the analog chassis. Remote circuit powered by it's own dedicated DC power supply.
Chassis finish options	No Charge - Real wood veneers Call - Real wood burl veneers Call - Hardwood chassis' designs are based on a per order basis depending on the wood of choice. For available wood veneer and/or hardwood options, click HERE
Tube Upgrade	We recommend looking at our Recommended Tubes page and choose a tube that best meets your preferences. You can order these tubes direct from this page and have then sent directly to us or you.
Warranty	5 Years (transferable) on all parts and labor 90 Days on supplied tubes Unauthorized parts substitution will void Warranty. Bella Extreme is the ONLY authorized facility to make any changes or modifications to the circuitry.
Availability	Now ! All units are built to order by hand in our commercially located workshop in Endicott, New York, USA. Lead time is typically 8-12 weeks from order to shipment depending on the individual configuration and work load.