I’ve finally got around to making some demo recordings to compare the sounds of my three different EchoTapper Vintage Echo units. In case you haven’t been following the story in this blog, I have (so far) build three different incarnations of the eTap2HW echo machine based on the original work of Piet Verbruggen.
Piet created the DSP programming of the Spin Semiconductors FV-1 chip which provides the emulations of the various vintage echo machines and he also designed a motherboard with a Fetzer Valve preamp and other support circuitry on which the FV-1 module is mounted.
The Units Under Test
- Mark I – is a manual unit built on Piet’s motherboard design with a modified FET preamp. The modifications involve re-biassing the FETs following the work done by Steve Mitchell.
- Mark II – is a fully automated version, also using Piet’s motherboard design, with the original FET biassing, with the addition of an Arduino Uno running my automation software
- Mark III – is a fully automated unit, with a two channel valve preamp using two 6N3 dual triode valves obtained ready-built from Hong Kong via an eBay seller. The unit uses an interface board designed by Eric Thacker to interface between the preamp, the FV-1 module and the Arduino Uno.
The units were connected, in turn, to the HI input of a Laney VC15-110 amplfier. This is a 15W all valve amp with a 10″ Custom Jensen speaker. The amplifier controls were set as follows
Clean Chan, Volume = 5, Bright Sw. OFF, Bass = 5, Mid = 5, Treble = 5, Reverb = 3, Tone = 3
The guitar used was my custom built ‘Hank’ with Fender 57/62 Vintage pickups. The bridge pickup was used throughout with the guitar volume control on full (10).
The sound was recorded using a Samson CO2 condenser microphone placed approximately 9 cm out from grille cloth, and about 15 cm in from Left edge of cabinet. The microphone was connected to Channel 1 on a Focusrite Saffire Pro 24 audio interface, on which the gain was set to 6.
The sounds were recorded (one at a time ;-)) at 48 kHz, 24 bit WAV, on separate tracks in a Reaper DAW. A send was created for each track and the signals were sent to a separate FX track which had an EQ and a Reverb plugin added. This ensures that all the recordings receive exactly the same effect treatment before the final mp3 tracks were rendered.
EQ Plug-in Settings
Reverb Plug-in Settings
Echo Unit Settings
The echo units were set as follows, essentially to attempt to replicate the same settings as far as possible. The differences in the three preamps would have a bearing on where the input Level controls of each unit should be set but the two FET-based units both had their input Level set to 5. The valve unit has an input Level and an Output Level control so it’s difficult to compare these directly with the FET units.
The Mark II and Mark III units were both set to use the built-in Atlantis patch which is taken from the suggested settings of Dave Robinson. The controls on the Mark I (Manual) box were set to match this as well.
Echo Model 5: Echomatic II Classic, Wet/Dry 5 (126), Prog 3.5 (89), Feedback 5 (125)
The figures in brackets are the approximate stored digital values associated with the knob positions in this patch in the automated units.
The Level controls on the valve preamp were set as: Input Level = 7, Output Level = 6
The lead guitar has been kept fairly high in the mix so that the differences between the units (if any) can be heard more clearly above the backing track. All tracks were done in one take with no overdubs or punch ins.