Technical data
| Instrument | cello |
| Line | AGAPE |
| Quality grade | 436 AP |
| Build variant | HERITAGE |
| Top | Spruce |
| Back and neck | Maple |
| Warranty | 6 months |
| Company seat | Wernitzgrün near Markneukirchen |
| Item number | CG-C436AP |
Features
- AGAPE line, quality grade 436 AP
- HERITAGE build variant
- Fittings in rosewood instead of ebony
- Aubert bridge, French style
- Traditional design
- Sturdy construction
In practice
- The model number stands for wood selection and the amount of work put into the white, still unvarnished instrument: graduation of the top, finishing inside and out, choice of tonewood. The higher the number, the more time has gone into the wood and the rounder and more differentiated the sound. Our regular cello range begins at quality grade 424.
- The letters denote the series: varnish and set-up, that is pegs, end button, sound post, strings, chin rest and adjustment. In a photo you cannot see the difference between a 424 and a 428, but you can see whether it is an Agape or an Antique.
- We varnish exclusively with spirit varnish. The spirit evaporates, resins and pigments remain. Priming, staining, colour coats, intermediate sanding and sealing add up to around fifteen steps; because these are natural varnishes, one coat more or less may be needed until the colour is right.
- This series carries a thin varnish. In our experience an instrument with a thin varnish sounds more open and brighter.
- The Agape is our sturdy instrument, also for playing outdoors: hard-wearing varnish, powerful sound.
- Rosewood is the most visible departure from the house standard of ebony and makes the line instantly recognisable.
- SIGNATURE and HERITAGE are two build variants of the same line. HERITAGE is the traditional and sturdier version, SIGNATURE the lighter, modernised one.
- Guide values for string height at the end of the fingerboard: violin around 3.5 mm under the E and 5.0 mm under the G, viola 4.5 to 5.5 and 5.0 to 6.0 mm, cello 5.0 to 6.5 and 5.5 to 7.5 mm.
- In the first weeks the strings stretch and the bridge creeps towards the fingerboard as you tune. Both need checking; a readjustment after a few weeks is normal.
- Humidity 40 to 50 per cent at around 20 °C, up to 60 per cent unproblematic. Below 40 percent you risk slipping pegs, opening glue joints and cracks.
- After playing, take off rosin dust with a microfibre cloth and no pressure. No polish, no tincture, no alcohol on the varnish.
- After cold or heat, open the case only after fifteen to thirty minutes. Never leave it in a car, never check it as baggage.
- The company is based in Wernitzgrün near Markneukirchen. It has existed since 1884 and is run as a family business in the fourth generation.
- Six months warranty on defective components and workmanship.
Sound and physics
The air inside the cello body vibrates through the f-holes as a Helmholtz resonator (A0) at around 100 Hz, roughly a fifth above the open C string at around 65 Hz.
The twisting modes of the cello bridge lie at around 1 and 2 kHz; its height strengthens the coupling to the top and with it the bass. The sound post practically doubles the number of modes that shape the sound.
On a measured cello the body radiates particularly well in three regions, around 165 Hz, between 280 and 400 Hz and between 620 and 880 Hz; partials in these bands colour the tone much as the formants of a singing voice do.
On the cello a wolf note (a note that stutters or jumps at a strongly coupled body resonance) typically sits on the G string between around 200 and 250 Hz. It is a sign of strong coupling and occurs precisely in fine instruments; a resonator on the string between bridge and tailpiece draws its energy away.
The top is spruce; back, ribs and neck are sycamore maple. At 12 % moisture content spruce has a density of 380 to 470 kg/m³ and a modulus of elasticity along the grain of 9,700 to 11,000 MPa, sycamore maple 560 to 650 kg/m³ and 9,900 to 13,000 MPa. This gives a speed of sound along the grain of around 4,800 m/s for spruce and around 4,100 m/s for maple. Acoustics therefore sees spruce as the transducer with high radiation efficiency, and the denser maple as reflector and structural support.
Both woods are strongly anisotropic: spruce is around 13 times stiffer in bending along the grain than across it, maple around 5 times, which is why the vibration patterns of a top appear stretched along the grain. Across the grain spruce shrinks tangentially by 7.8 to 8.2 %, around twice as much as radially at 3.6 to 3.9 %.
We varnish with classic spirit varnish, which we colour ourselves with pigments; we do not use oil varnish. The build-up follows fixed steps: two coats of ground varnish that keep the colour varnish out of the wood, then colour varnish in as many layers as the shade requires, and four to six coats of top varnish.
Each layer dries for one to fourteen days depending on the varnish and temperature, and the work is done at an even 20 °C or so. Once fully dry, the varnish is rubbed down and polished with polishing oil and tripoli (a fine polishing powder). The instrument is varnished under the bridge feet as well; there the varnish is reworked so that the bridge sits snugly.
The fittings of the Agape cello can be either rosewood (Dalbergia latifolia) or ebony. At 12 % moisture content Indian rosewood has a density of 820 to 920 kg/m³.
From the workshop the Agape cello carries our German standard varnish; the more elaborate Antique varnish is possible as an alternative. All our cellos are built of solid wood, with back, ribs and neck of maple and a top of spruce.
Our experience
Our cello tops are seasoned for 15 years and more before they leave us. Our cello range consists solely of new instruments in full 4/4 size. We deliberately set the string height slightly above the recommended final setting of 5 mm at the A string and 6.5 mm at the C string, because a bridge is easier to lower than to replace.
All our tonewood, including that of our entry-level instruments, has been cut and stored for 15 years and more before we work it. Our maple comes from Bosnia, our spruce mainly from the Alps in Austria and southern Germany.
Freshly varnished instruments look matt before polishing; only afterwards does the varnish show its depth.
When another model suits you better
Players looking for a cello with an antiqued appearance built from several coloured layers of varnish will find it in our Antique cello.
Frequently asked questions
Where is the air resonance of a cello?
At around 100 Hz, roughly a fifth above the open C string.
Is a wolf note a defect?
A wolf note is a sign of strong coupling between string and body and occurs precisely in fine instruments. A wolf eliminator between bridge and tailpiece draws its energy away.
How long is the top of a Götz cello seasoned?
15 years and more before the cello is delivered.
Why is the top spruce and the back maple?
Spruce combines low density with high stiffness along the grain and radiates sound efficiently. The denser maple acts as reflector and carries the structure.
How long is the wood seasoned?
15 years and more before we work it.
Which varnish is used?
Classic spirit varnish, pigmented by us.
These texts hold decades of experience and a great deal of heart. They are protected by copyright, C.A. Götz jr. GmbH. Please ask us before any use. Thank you for your appreciation.
