> ## Documentation Index > Fetch the complete documentation index at: https://docs.orbit.devotel.io/llms.txt > Use this file to discover all available pages before exploring further. # Pick a voice-agent model preset > Choose between Balanced, High Intelligence, Ultra Fast, and Cost Saver — the curated transcriber + LLM + voice bundles for voice agents — and launch one as a ready draft agent from the picker. # Pick a voice-agent model preset A voice agent is three provider choices yelled at each other: which speech-to-text engine hears the caller, which LLM thinks, and which text-to-speech voice answers. The **Model Presets** picker ([/agents/model-presets](https://orbit.devotel.io/en/agents/model-presets)) bundles those three into one curated configuration per card, so you pick a latency-cost-quality tradeoff and get a working draft agent in one click instead of hand-tuning provider dropdowns. Every preset ships the same dependable foundation — Deepgram transcription and a Cartesia voice — and the presets differ only on the model tier and the lane it runs on. What you are choosing is the reasoning tier. ## 1. The four presets Each picker card shows the comparison that matters up front: estimated time-to-first-audio latency (p50), estimated blended STT+LLM+TTS cost per minute, and a 1–5 reasoning-quality rating. Open **Preview** on a card for the full description and its recommended-for list. | Preset | Model | Latency (p50) | Cost per min | Quality | Best for | | --------------------- | ---------------------------- | ------------- | ------------ | ------- | --------------------------------------------------------------------------- | | **Balanced** | Claude Sonnet 4.6 | \~900 ms | \~\$0.09 | 4/5 | General support, sales, scheduling — the default when unsure. | | **High Intelligence** | Claude Opus 4.7 | \~1,400 ms | \~\$0.22 | 5/5 | Multi-step negotiation, technical troubleshooting, compliance-stakes calls. | | **Ultra Fast** | Claude Haiku 4.5 (fast lane) | \~450 ms | \~\$0.05 | 3/5 | Sub-second barge-in lines, high-volume triage, short scripted flows. | | **Cost Saver** | Claude Haiku 4.5 | \~650 ms | \~\$0.03 | 3/5 | Very high volume, simple conversations, margin-first lines. | The numbers are curated comparison estimates — a selection aid, not per-call SLAs. Use them to choose a tier, then measure your own traffic on the [VAQI dashboard](/voice/vaqi) once the agent is live. **Balanced** is the recommended starting point: Sonnet-tier reasoning at a mid-market per-minute price. If you do not have a specific constraint pushing you elsewhere, start here and re-tier up or down as VAQI tells you. **High Intelligence** trades latency and cost for the deepest reasoning Orbit runs. Pick it when a wrong answer costs more than 500 ms of hold time: collections negotiation, multi-step technical troubleshooting, calls with financial or regulatory stakes. On live traffic it pays for itself when the voice agent's resolution path needs multi-step tool calls. **Ultra Fast** routes the session onto the low-latency fast-model lane, which is what sub-second barge-in needs. Callers interrupt often; if your agent is still finishing a sentence from the previous turn when the caller speaks, your barge-in success rate drops and the line feels broken. Barge-heavy inbound triage lines (order-status lookups, appointment confirmations, routing to a queue) belong on Ultra Fast. **Cost Saver** is the same Haiku-tier model as Ultra Fast, but off the fast-model lane and tuned for shorter replies — so at very high volumes the per-minute bill drops to roughly a third of Balanced's. It trades a few hundred milliseconds of first-audio latency for the cheapest per-minute rate. Outbound campaign lines and read-only simple lookups ("what's my balance?" "when is my appointment?") belong here. ## 2. Instantiate one, open it in Agents Studio From the picker, two paths converge on the same draft: 1. **Preview a preset.** Click **Preview** on the card, read the full description and the recommended-for list in the dialog, then click **Use preset** from there. 2. **Use it directly.** Click **Use preset** on the card — the instantiate POST is guarded so a second click while the first is in flight never mints two agents from one intent. Either path `POST /agents/model-presets/:id/instantiate` (owner/admin only) → a **draft** voice agent is created pre-wired with the preset's model, transcriber, voice, temperature, and token ceiling. A draft never answers a caller until you activate it. The full API shape is at [Model presets](/api-reference/agents) on the Agents API page; you can also override the agent `name` and `description` in the same call. The picker routes you straight to the new draft agent's [Agents Studio](/agents/\[id]) page — the `/agents/:id` surface — where you rename it, edit the generated starter prompt, and pick a different Cartesia voice. The preset's job is the model/transcriber bundle; the voice casting and prompt fine-tuning happen in the studio afterward. ## 3. Tune from a preset vs hand-tune provider dropdowns There is nothing special about an instantiated draft: it is a normal draft agent whose `stt_vendor`, `fast_model` lane flag, `model`, and sampling parameters were filled in by the preset. Everything it ships you can still edit afterward in the agent's versioned config. The preset is a coordinated starting point, not a lock-in. Use a preset when you are deciding "which reasoning tier should this line run?" — that is a decision, not a configuration. Override by hand (in the studio or via `PUT /agents/:id`) when you already know the constraint: barge-in lives or dies on the `fast_model` lane flag, and per-minute cost lives on the model id plus the max-token cap. If you override by hand, set those two knobs together — a cheaper model on the standard lane still won't respond fast, and the fast lane on a Haiku-tier model still bills at Haiku prices. The preset exists so the three knobs move together coherently. ## 4. Compare two agents before/after with VAQI Preset choice is not permanent, and the safest re-tier loop runs two agents side by side: keep the current production version on one, instantiate a second from the candidate preset, and read them against each other on the [VAQI dashboard](/voice/vaqi) (Voice → Voice Agent Quality). Watch the three VAQI families after routing live traffic onto the candidate: * **Latency** — the candidate preset's real p95 time-to-first-audio vs the estimate on the card. The dashboard flags a warning past 1,200 ms. * **Barge-in** — on Ultra Fast especially, the success rate on interruptions is the number to move; the rate of interruptions itself usually stays. * **Cost** — the estimated per-minute on the card vs the realized per-minute spend, visible per agent. The full before/after promotion loop (persona simulation, stage-by-stage canary, rollback) is covered in [Safely Roll Out an AI Agent](/guides/ai-agent-rollout-pipeline); VAQI is the live-traffic read you use inside that loop after a preset lands. ## Troubleshooting | Symptom | Fix | | --------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `403` on **Use preset** | Instantiate is owner/admin only. A developer or member role can browse the preset list but can't mint a draft. | | Clicked **Use preset** and no new agent appears | The draft always lands in `status: draft` — check the Agents list's draft filter before assuming the create failed. | | The new draft's prompt is generic | Instantiate stamps a neutral starter prompt (concise voice replies, clarify, offer human handoff). Rewrite it in the studio — the preset fixes the model bundle, not the wording. | | VAQI says latency regressed after switching presets | Compare the pipeline split (STT vs LLM vs TTS) on VAQI: a TTFB spike with flat STT/TTS points at the model lane, not the network. | ## See also * [VAQI dashboard](/voice/vaqi) — live latency, turn-taking, and barge-in metrics to compare presets against real traffic. * [Author an AI Agent from a Prompt](/guides/agent-from-prompt) — the from-prompt drafting flow that also pins a preset on the generated draft. * [Set your organization's LLM provider preference](/guides/llm-provider-preference) — the provider-level lineup (free base vs premium tier) that sits under the preset's curated lineup. * [Safely Roll Out an AI Agent](/guides/ai-agent-rollout-pipeline) — persona simulation, canary stages, and rollback for the before/after compare path.