Amplifiers

This page last updated September 16, 2020.

DeArmond Tube Amps:

In 1959/1960, six amplifiers using vacuum tubes (thermionic valves) were introduced under the DeArmond name.  Four of these were also branded as CF Martin as follows:

DeArmond Model R5                  – CF Martin Model M110 (RM5)

DeArmond Model R5T               – CF Martin Model M110T (RM5T)

DeArmond Model R15                – CF Martin Model M112 (RM15)

DeArmond Model R15T             – CF Martin Model M112T (RM15T)

DeArmond Model 25T               – No CF Martin equivalent

DeArmond Studio Amp             – No CF Martin equivalent.

DeArmond’s in-house names for the CF Martin-badged amps are shown in brackets after the official names above.

DeArmond catalog extracts are shown with each individual amp description.

The following is a single page extract from a CF Martin Tube amp catalog, covering their four models:

(photo courtesy CF Martin)

CF Martin separately commissioned a series of transistorised amplifiers from Allen Organ, a company in Lehigh Valley, Pennsylvania.

A schematic diagram and instructions were supplied with every DeArmond and CF Martin amp.  A label was applied to the inside of every amp showing the vacuum tubes layout, the amp’s serial number and on some amps, a code that may identify the employee in charge of assembly and testing.  See typical label below.

 

Every DeArmond and CF Martin amp with a tremolo circuit , identified with suffix T in its title, was supplied with a foot switch, Model TFS-1, either hardwired or removable, by means of a jack socket on the underside of the amp chassis.  The switch itself was manufactured by Leviton, and is the same type as used in the controls box for the Models 1000 and 1100 Rhythm Chief pickups.  The foot switch is shown below:

Foot switch TFS-1 (Photo copyright Brian Howard).

Erie Packs:

An interesting feature of some tube amps sold under both DeArmond and CF Martin brands was the inclusion of one or more electronic circuits in maroon-coloured hard resin encapsulations.  These items were called ‘Erie Packs’ by the employees and were most likely included to prevent copying of the circuits by rivals.

The following information is from DeArmond’s own in-house manuals (Courtesy Tom Ricketts, Toledo):

Part:                            Description:                                                                              Amp ref:                                         Quantity:

TBA-196.         Strip Pac. (Invertor) Erie Resistor # EP-9097                                  R15 & RM15                                        1

TPA-197          Strip Pac. (Invertor) Erie Resistor # EP-9097-1                               R15T, RM15T & R25T                         1

TPA-198.         Strip Pac. (Input) Erie Resistor # EP-9098                                      R15T, RM15T & R25T                         1

TBA-199         Strip Pac. (coupler) Erie Resistor # EP-9099                                   R15T & RM15T & R25T                      1

TBA200          Strip Pac.   <— Text is unreadable here —>                                    R15 & RM15                                        1

TBA-201        Tone Pac. CRL#YFE-020-03A4B                                                     R25T.                                                   1

 

An Erie Pack can be seen in the schematic diagram below, marked EP-9097, with ten numbered connections exiting from it.  The item itself can be seen in the lower centre of the amp chassis in the rear view of the amp.

Rowe-DeArmond’s 1965 catalog includes the following note on it’s last page:

‘DeArmond Amplifiers are booming in a big way!

Watch for the expanded line of DeArmond “amps” for 1965-66, from Rowe Industries of Toledo.’

Unfortunately, these amps did not appear, but Rowe Industries’ schematic drawings exist for the Model R6-T (undated and incomplete) and the Models R30-T and R60-T, both dated April, 21st, 1964.  See below:

Rowe Industries Amp R – 6T Schematic Title Block, undated.

Rowe Industries Amp R – 30T Schematic Title Block dated April 21, 1964.

Rowe Industries Amp R – 60T Schematic Title Block dated April 21, 1964.

A chassis exists for another amplifier, the DeArmond Model R 10T, complete with copper-finished control panel.  This amp was also not produced commercially.

Rowe Industries Amp R 10T Control panel (above four photos and text copyright Dave Walters, Toledo and ex-DeArmond)

CF Martin Tube Amps:

These were as standard DeArmond models with cosmetic differences only, including a different baffle material, black fabric covering, a chrome control panel and black knobs:

DeArmond Solid-state Amps:

In 1970, Steve Tosh joined the company He designed a range of solid-state amplifiers and speaker cabinets for guitars, basses and PA as shown below.  Steve was appointed CEO of the deArmond side of the company in about 1977: